Green Building Forum - All Discussions

Screeding Over Underfloor Heating Pipes and Types of Insulation

EdF — Thu, 05 Jul 2007 12:42:52 +0100

About to lay 65mm of screed, but I'm a little confused how to mix it, wettish or dryish? I've seen both done (after the event). If it's fairly wet I expect it will be easier to put down and level. Should I put a retarder in it to help out, how about a plasticiser?
I discovered that 'almost everybody' in my area lays Kingspan or similar insulation under UFH. Apparently this is not ideal, extruded polystyrene is better, such as Dow Floormate or Knauf Standard Floorboard. The proprietor of the biggest UFH specialist in my area advised me and showed me samples. Kingspan etc is not so resistant to compression and can crumble, the two I've mentioned don't, he said. Probably better if there's a lot of big footed contractors going to walk all over it before it's screeded.. I found Sheffield Insulation were cheapest where I live, also Warrens in Chesterfield were not bad.

100% Airtight passive house â€“ insulation, windows etc. advice needed!

steveleigh — Mon, 28 May 2007 11:35:38 +0100

Copper, and a plumbing puzzle

Bluemoon — Thu, 27 Sep 2007 21:05:21 +0100

I'm a DIYer who does plumbing once in a blue moon. I ordered flexible tails to connect the bath filler, and the bidet mixer comes with them included. Here is the puzzle, why have I installed 22mm copper tube to feed the bath, when the bore of the tail is only 13mm? Similarly, the basin has 15mm pipes but the tails and mini valves have a bore of around 8mm. I wonder if the fittings had clear bores designed into them, we could all use smaller pipe? Or is it me? Copper is very expensive at present due partly to increased demand. Smaller pipe would use less metal, and be greener due to less energy used in production and carriage.

Rainwater harvesting trade off against drain requirements

richy — Sun, 30 Sep 2007 11:42:01 +0100

The 20 sqm cabin in the woods is to have little more elaborate than a water butt for rainwater harvesting and watering the garden, but the drainage requirments to keep BC happy are to be 2.5m cubic M soakaway. Can I reduce this by getting more serious about harvesting?

Recycling/Re-using building waste

Mike George — Sun, 23 Sep 2007 07:05:09 +0100

How much building waste goes to landfil each year and how much could be re-used/recycled?

Where I live the council will not allow 'vans' to use their amenity tip unless by prior arrangement. Even if you were to do so there is still the legal requirement to be a licenced waste carrier.

Is it time for governmant to provide monitored facilities where builders could pay a nominal fee to take some of their waste? This could be limited to easilly recyclable/re-useable materials.

Re-usable items such as timber sections and bricks could even be sold back to other builders.

Is this a feasible idea?

District heating pipes - beware

GBP-Keith — Thu, 27 Sep 2007 17:54:28 +0100

Anyone planning on using some district heating between buildings beware of the systems that use pulled through insulation. I think they must stretch it with the pulling process as I've just been servicing the entry/exits of the piping and have discovered that the internal insulation has completely vanished down inside the ducting!

If you are going to use this type then I suggest that you extend the tails so you can shorten the ducting and bend the insulation out over the tail and clamp it on with jubilee clips.

In the picture you can see that the one on the left is devoid of inner insulation. A tape measure pushed down the pipe revealed 4mm and probably still shrinking. All I can do now is restrain the outer one as suggested above and pour something like polystyrene beads down to hopefully fill the void.

Shading to windows

tony — Fri, 28 Sep 2007 00:17:07 +0100

What angle of shading should be used for south facing windows.

Should a window be fully shaded by slats or a canopy/ verandah at mid day from June to the end of August or what and how?

combi hot water from thermal store solar and wood stove

martinlta — Fri, 28 Sep 2007 11:05:22 +0100

Hi

Is it possible to connect the output from a mains pressure hot water supply (Heated by a thermal store - solar + wood stove input with plate heat exchanger PX for the mains pressure side) to the input of a Puma combi gas boiler on the hot water side. The Puma manual states mains pressure cold water input, but if I turn down the hot water temperature output setting on the boiler to low (40-50C), and kept the mains pressure hot water input from the Thermal store PX to no more than 70C, would the combi not fire up until the temperature of out put dropped to <40C. The Combi has the std overheat stats in addition to the output hot water temp control stat.

Any thoughts

Metering of Low or Zero Carbon Technologies

Iain — Thu, 27 Sep 2007 09:24:07 +0100

I'm in the process of writing an article on the above topic and wondered if there was any anecdotes people on here would like to share?

On speaking to BMS providers I've found that they're more than capable to sub-meter mains supplies to circuits but less knowledgable about embedded supplies. Surely the performance of these technologies needs to be fed back into the design process to assist developers and planners select the best performing system?

Have you found installers to be poor in metering their systems? Are their systems easily integrated into larger building energy management software?

Any comment much appreciated.

Self Build Books

Iain — Thu, 27 Sep 2007 15:20:32 +0100

I've recently found out that I own part of a field in the north of Scotland. Being an industry professional I've always wanted to get my hands dirty and build my own house, my only problem being my lack of experience in small scale construction matters.

Can anyone recommend book that'd give me a crash course in the process? I'm well versed in my field there are gaps in my knowledge especially when it comes to choosing one construction method over another (e.g. double skinned brick with cavity versus timber framed).

Any help appreciated.

Also, has anyone built their own house and documented the process? I'd be very interested to read these. Again, many thanks. :smile:

Ridge Tiles

tony — Tue, 25 Sep 2007 16:34:05 +0100

It would be very interesting to know how many readers have had to have a ridge tile re-bedded onto the roof of their house. I suspect that many readers, some of whom live in quite new houses, have had ridge tiles blown off their roofs at some time during the past few years. Certainly it would be true to say that far too many ridge tiles have been coming adrift in recent years. Why is this? There are several reasons:-

One reason is that, in my view, all ridge tiles should positively mechanically fixed in addition to cement mortar or other bedding which is used. The majority of ridges are still put on roofs using mortar and although many specifications say â€˜fully bedâ€™ this is very rare to find. I feel that we should be using ridge tiles that weigh about twice as much as they do at present. It should be borne in mind that most Victorian ridge tiles havenâ€™t moved since the day they were laid despite the fact that the mortar under them has turned to dust.

We must therefore mechanically fix down ridge tiles in all locations in order to provide longevity to our roofs.

Roof insulation for existing flat roof extension

nkmanglam — Thu, 27 Sep 2007 07:38:18 +0100

Hello All,

I have approx 30 sq m kitchen area and a double garage as flat roof extension. This house was built in 1968 and very poorly insulated. What is the best option for me to insulate flat roof? I would prefer if insulation can be done externally.

I must mention that i have future plan to build above this extension. Total floor area of this extension will be apporx. 100 Sq meter. Its in two level. Kitchen one is higher and garage is lower.

My main aim to reduce my tota energy requirments.

Thanking You

Kind Regards

Niraj

Beit and Braces examples of wastefull overkill

tony — Wed, 12 Sep 2007 08:27:10 +0100

In the days when we first started to use wire ropes for lifting loads we used to pass the rope through an eye or cleat and fix it back to itself with a wire rope grip (a u-bolt with a flange) The trailing free end of the rope would be tied onto the rope to keep it out of the way. This worked well but after a couple of mishaps where the u-bolts were not inspected and they either were damaged or worked loose through overloading it was decided to use two wire rope grips should be used in case one failed between inspections. No problems ever occurred but someone eventually decided that three would be better than two and this was common safe practice for many years. That was until some safety manager in an office saw a picture and thought that we should halve the risk by using SIX; this became law!

How much of this kind of thinking is wasteful of resources without adding benefit?

Insulation problem in 1968 built dormer house

nkmanglam — Tue, 25 Sep 2007 20:20:37 +0100

Hello All,

I have joined this forum today. I have been reading postings oin this forum for quite sometime now and finally i got time to share my house renovation problem.

I have lived in this detached 4 bedroom dormer house (buit in 1968) since october 2005. I moved in this house in 2005 winter, it was very cold even when we had central heating on for 24 hours, which increased my gas bill to almost Â£200 a month. This house didn;t have cavity wall insulation, i got this done in january 2006. Soon after that i got central heating quote and got whole of central heating replaced (indluing all old radiators). After getting new central heating installed, i thought my gas bill would reduce drastically as i have condesning combi Worcester Greenstar Highflow 440 instaled now. But contrary to my imagination my monthly gas bill is still close to Â£150 a month, but i must admit this house has become habitable now.

I was reading on internet that if i have undefloor heating done it will reduce my gas bill further as ambient temperature for UFH is only 19 degree compared to 21 degree for convetor heating. I am told my my ocal building inspector that i will have to use 50 mm underfloor celotex insulation because i have suspended timber floor. I have decided to exceed this isulation requirmenet and put 100 MM celotex insulation board. I have been told that wet under flor pipes should be cliped on celotex insulation between timber joists. And to increase thermal mass i should use 25 MM sand and cement screed to cover UFH pipes which will keep the floor warm for longer duration.

My question relating to Under floor heating is that does it really reduces energy requirements ? will 19 degree will be ambient temperature if i have UFH? Do i ned a joiner or a builder to put these insulation board and UFH pipes ?

My Next worry is that i on first floor carpet floor gets really cold because and in windy days carpet gets lifted upto 1/2 inch due to wind coming between ground floor roof and first floor flooring. i had roof repairer coming and they claimed that they fixed the problem by changing felt. BUt i can still feel the cold air coming under my first floor carpet and whole carpet is very cold. though OVERALL TEMPRATURE goes tro around 21 to 22 edgre when we have our central heating on.

Both side of my house has dormer roof which is below window. I have feeling that both sides dormer roof need repairing. Do i need this dormer roof repaired from inside or outside?

Both side of dormer has not got brick wall but rather it has plaster board which is very very cold in winter.

DO i need to get both side of dormer roof changed ? Behind this dormer roof there is only single brick wall.

What is the best method to achieve below 1 U value for my house?

Do i need to contact a structural engineer or an insulation consultant ?

Because one side of roof felting was repaired by a local roofing company and charged me Â£700 and said he has insulated external wall so to prevent any wind coming under my first floor. This company gave me 10 years gurantee and i rang them to complaint that I still have wind coming through my floor and i was told that this
roofing company is no longer in business now.

Is it norma to leave ventilation for joists on the first floor between ground floor roof and first-floor floor?

I have my roof well insulated with fibre glass. Do i need to insulate inside of roof frame with celotex board?

My house is on seaside and its very windy in winter.

I am quite reluctant to contact local builder before i really know what needs doing in my house.

I will be grateful for your help and advice.

Thanking You al in advance.

Regards

Niraj

Do you live in an Eco House?

greenesthomes — Tue, 25 Sep 2007 14:51:26 +0100

ARE YOU THE PROUD OWNER OF AN ECO-HOUSE?

Cineflix Productions are making a series for Discovery Planet Green and HGTV called "World's Greenest Homes". If you live in or helped design a home which is not only architecturally stunning but has strong eco-credentials, we would love to hear from you. Your house can be anywhere in the world.

For more information please contact Nicky Huggett, Assistant Producer on nhuggett@cineflix.com or call 0207 428 7430.

Thank you!

Should I fix very wet green oak rafters

oiseaux — Tue, 18 Sep 2007 02:43:50 +0100

Hello, I am slowly (very) constructing a garden room with a tiled roof using old oak for glazing and main frames, and green oak for the rafters. It appears to be extremely wet and I guess very new. I have read on this forum that green oak will shrink by 10% and I am concerned that my 3.5 metre long rafters will contract and take other frames with it. Should I leave the rafters in postion and covered but not fixed until they seem to have dried out. Your comments would be most appreciated.

rotten window repair

hippychippy — Sun, 23 Sep 2007 01:28:31 +0100

I am replacing the bottom rail and lower section of the stiles on 2 largish - ( 1280 X 540 ) & elaborate victorian casement windows .The plan is to join the old & new stiles with a glued and (brass) screwed splice. I am not entirely sure that this will stand the test of time, which I would like it to do. however, my time doing the work is relevant and this method is simple . Can anyone suggest an alternative method ? Observations or options welcome

Zero Carbon building in Wales

ted — Tue, 25 Sep 2007 19:07:58 +0100

The Welsh Assembly Government are hoping to enforce zero carbon new build in Wales from 2011 by devolving control over new Building Regulations.

There is some public consultation in process and you can make your views known by responding to the questionaire available for download from here: http://www.assemblywales.org/sc-consultation_letter_web-e.pdf

Written responses are due by 19th October 2007.

This consultation is regarding households only. Later consultations will cover transport, industry and public sector, agriculture, energy production, and planning.

Causes of damp

pdurkan@yahoo.co.uk — Sun, 23 Sep 2007 21:02:50 +0100

When we moved into our house, there were some woodworm living in the cupboard the stairs. A surveyor attributed this to damp due to vents blocked by a dining room extension; covered the wood in boron & installed two vents in the dining room floor.

However, the hallway with the cupboard under the stairs smells awful musty & I'm wondering if we still have a problem.

Does anyone know if there's a cheap way of checking for damp? Is there any way of telling if floor vents & external air bricks are letting enough, or too much, air through?

Cheers,
Paul

New roads -- no more needed?

tony — Fri, 21 Sep 2007 14:59:24 +0100

Do we need ant more new roads?

Floors - major feature in Winter GBM

GBP-Keith — Tue, 25 Sep 2007 12:21:44 +0100

The main feature of the next edition of Green building magazine will be on floors. Anyone wishing to propose an article or even write something for us on their favourite design, practical experiences or theory then please get in-touch with me well before October 25th please.

Thermoplastic roofing membranes

Mike George — Tue, 04 Sep 2007 21:11:12 +0100

I am overseeing an extension which requires a flat roof. The above has been suggested to me. The problem is that I know nothing about it. Anyone help? Is it good bad or ugly? Is there a better solution? Roofcrete? Fibreglass?

Retailer wanted for quality wooden roofshingles in GB

sindelkatus — Mon, 24 Sep 2007 15:20:20 +0100

Hello

We produce wooden roofshingles from quality pine and spruce and we are looking for a retailer in GB in long run. The agent/partner would have some experience and knowledge in roofing. In case You or perhaps Your friend would be such person, we would be very glad for being contacted to vihmand@hot.ee
Our production capacity is at the moment 120 000 shingels per month which equals at least 1600 square meters of fine-tuned roof.
Conditions flexible.

Excavation on tricky site.

richy — Sun, 23 Sep 2007 19:18:36 +0100

I have a job coming up hand digging some foundations for a cabin at the top of a small hill in the woods. The 4 -5 cubic metres of earth which is removed will need to be taken away from site, there is no choice, the owner insists. Getting it to a skip will involve negotiating a wheel barrow over drystone walls and down bankings.

I just came up with an alternative idea; to rig up a zip wire or arial runway from a tree at the site down to some scaffolding sheer legs next to the skip and making a sort of hopper or scoop out of a plastic barrel. The idea being to fill the barrel by hand shovel and then let it wing it's way 30ft or so to the track where another line pulls it into the tip position just above the skip! Then it's gets hauled up by a line for the next load.

Sounds wacky and will cost about Â£100 in kit to try it, but it will have minimum impact on the surroundings compared to dumpers or tracked vehicles.

Will it work? Anyone any experience of anything similar? I'm hoping it will save a lot of really hard work!

constructing a cellar

howdytom — Thu, 20 Sep 2007 19:45:00 +0100

I want to include a cellar in a barn conversion project, but whats the best construction.
It would be nice not to use concrete, my subsoil is mainly boulder clay 16foot on limestone. The site is fairly level so digging a drain would be impossable unless I go 300 meters !. I used to live in an old house with cellars it had limestone walls but I have no idea what they used behind as a water barrier... maybe nothing. If I dug it out cast a concrete floor with DPC , built limestone walls, what would be best for the roof ?. I would hope to end up with an internal size of 3meters by 5meters:confused:

Fitting wooden windows to a timber frame house

smallcog — Sat, 22 Sep 2007 21:29:00 +0100

I'm in the process of building a timber-frame house in the west of Ireland ( photos can be seen on http://awoodenhouse.thisbetterworld.org ). The initial frame is up, all stud work in place, with openings in the studwork for all doors/windows. The studwork is then sheathed by OSB with a membrane wrapping the house outside the OSB. My question is concerning the installation said doors and windows and how to ensure that all sills casings etc. are perfectly waterproof. I hope to install the doors/windows before doing the final outside layer which will be hotizontal timber nailed on to vertical battens. I don't want to use concrete sills and since I'm not plastering I'm wondering about the options. Do "kits" exist for the flashing around timber windows ? Any recommendations on whether I could do the lot in timber and lash on the sealant all over the place or whether its a better idea to look for aluminium flashing ? Any potential pitfalls if I went for a no-sill solution and had the windows flush with the outside wall ?
All comments welcome / Colm

foam vs rockwool

mitchino — Tue, 11 Sep 2007 09:33:33 +0100

I am framing and lining cavity walls internally. The cavity will eventually be filled. I am about to insulate between the frames which will then get a vapour barrier and plasterboard. I can either insulate with 50mm rockwool batts, which I already have plenty of, or I could order kingspan or equivalent and use that. The frames are 40mm thick, so I can squash the batts in, but the kingspan would have to be 40mm or under.

What I want to know is, will it make a big difference in terms of heat loss if I go the easier route and use the batts?

I just got planning permission for my nursery

Katymac — Tue, 18 Sep 2007 21:01:56 +0100

I am so happy

It was unanimous

So serious planning starts here (plus advertising)

Rammed Chalk

TracyS — Thu, 20 Sep 2007 10:37:03 +0100

I have just bought a rammed chalk house in Hampshire and am struggling to find a builder who will take on renovation work. Does anyone know how I can find someone with the expertise? Surveyors have not been helpful.

Why inward opening doors?

Henry Sears — Thu, 06 Sep 2007 22:36:36 +0100

Not exactly a green building issue, but I think this forum's got some intelligent heads participating, so here goes.

I'm renovating a timber house at the moment, and two external door frames need replacing, having rotted out at the bottom due to water getting into the joints at the bottom of the frame.

It would seem to me to offer several advantages to hang external doors to open outwards (although i can see the difficulties when they're at the top of flights of steps).

Weather sealing would be more easily achieved, and the bottom cill could have a nice flashing that stood up behind the bottom of the door. Also the door wouldn't encroach on indoor space when opened.

And bailiffs would find it much harder to force entry!

So why do Brits always hang 'em to open in?

Add a natural homes map to your blog

naturalhomes — Fri, 14 Sep 2007 04:13:18 +0100

Low-impact bloggers can now include the natural homes map in their own blog. You can include the whole collection of homes in the register, with all the links back to the owner's website, or include only the home type you are keen on like straw bale or earthship.

I've never published a blog before today, so mine is pretty much empty at the moment but here it is http://ecooliver.blogspot.com It shows the straw bale map version of the natural homes map and gives you a link to natural homes where you can collect the code to include a map in your own blog.

You can collect the code directly from here http://naturalhomes.org/naturalhomesmap.htm if you like.

I'd love to have any feedback from anyone...

Oliver

Eco Insulation Thickness

mitchino — Wed, 19 Sep 2007 20:14:22 +0100

Do any of the eco loft insulation products like thermafleece et al come thicker than 100mm? I know I can double/triple up, but would be easier if I could start thicker!

Heavyweight verses lightweight construction

Chris Wardle — Sat, 08 Sep 2007 20:00:07 +0100

Did you hear the guy from Arups on the news today? They are claiming we are building housing which will be inappropriate for the warmer world we will be inhabiting later this century because it is increasing lightweight timber frame and doesn't have the thermal mass and passive cooling traditional in warmer areas like the Med. He thinks we will all be sat in plasterboard boxes with the aircon on...

I thought they might have produced a report but I can't find anything on their website. What do people think?

Past the magic 1000 barrier

GBP-Keith — Thu, 20 Sep 2007 19:39:43 +0100

I would like to say a big thank you to all who have joined the green building forum and have made it such a great place to discuss our pet subjects.

Now we have over 1000 members, we really do have a green building community that is happy to share, discuss and promote our ideas. Well done to everyone.

Tricky Loft Insulation Installation - What's best?

mitchino — Wed, 19 Sep 2007 23:20:00 +0100

I have just cleared out my extensive loft area, removing a lot of patchy very thin rockwool, vermiculite, bits of carpet etc. The loft is of a very complex, multilevel construction as our house has had two different extensions. There are some bits with 100mm joists, some with 200mm joists, some areas have 200mm joists with 100mm joists on top at right angles. Most of the roof is at a very low pitch, and I won't be able to achieve much thickness at the eaves.

I want to insulate effectively up to 300mm, but using batts or rolls will be very difficult in some areas. I may need to use a combination of fibre insulation and loose fill.

How should I approach the job? I was thinking about using warmcel up to the top of the joists (so in some areas it would only be 100mm deep) then cross laying batts to get the thickness up.

I'm also concerned about natural insulation and mice - we always have a lot of mice in the winter, I've heard they just love to nest in the likes of thermafleece/warmcel, is this true?

Lost in Transmission

biffvernon — Wed, 19 Sep 2007 21:28:32 +0100

Lost in Transmission is a report just published by the Sustainable Development Commission concerning the future organization of our energy supply industry. Perhaps tangential to Green Building, but with 46% of UK CO2 emissions coming from buildings, it's an important document for anyone with an interest in the energy use in buildings. The matter of household generation and grid tie up is particularly addressed.

http://www.sd-commission.org.uk/pages/ofgemreview.html

http://www.sd-commission.org.uk/publications/downloads/SDC_ofgem_report.pdf

Powering down a 1960s property.

SimonH — Mon, 17 Sep 2007 13:37:55 +0100

Iâ€™ve been looking at ways to make a 1960â€™s house that Iâ€™m in the process of buying as energy efficient as possible. Iâ€™ve not reached any conclusions, but this seems to be the place to startâ€¦ Insulate, insulate, and insulate. Loft, walls, floor and windows. If I get this right first, then I can think about which heating system to go for. Given the house is mainly brick cavity with suspended timber ground floor Iâ€™m considering the following options. Any ideas for better ways to do things would be appreciated. Also any books that specialise in opportunities/problems while "updating" properties â€“ Iâ€™ve read the bibles and whilst filled with info, they focus mainly on new build.

Floors
Get the floors up, affix under panelling, fill with warmcell. Or is it better to go with a 2 ply expanded foam over the current boards laid to stagger the gaps. (Losing > 100mm of room height?) Iâ€™m considering underfloor heating for the downstairs so this may make more sense. What thickness is effective? I.e. Iâ€™ve seen the UFH companies now have 15mm insulation containing the channels for the pipes. Doesnâ€™t seem thick enough to me!?

Walls
Get the cavities filled with expanding foam with the least GWP and 0 ODP. This should provide a more air tight seal than beads or blown fibre â€“ correct? Once this is done I should end up with a U value of 0.5-0.6 so not good enough. Therefore I need to consider external insulation. This will be expensive but could get me down to a U of 0.15. (Been playing with spreadsheets to work it out). As I have a 60â€™s house with some cross wall type panelling, now replaced with UPVC :-( I think I will need external insulation anyway as itâ€™s canâ€™t be cavity filled. I think I have 2 problems with external insulation, 1) Changing the appearance of the house. 2) Getting the detailing correct. Probably need to engage a designer to see what the effect will be like. Would be nice to sell / give away the upvc panelling and replace with cedar/larch etc. However itâ€™s on an estate and may stick out a bit!? I have considered using brick slips, to stick on the insulation, trying to keep it as it looks now, but is that just bonkers? Maybe not for the front, and then render everywhere else. I donâ€™t mind having unpainted wood in the infill sections as I think that looks quite nice. Is it cedar that eventually goes to that nice silver grey colour?

Interested to hear from anyone who has used external insualtion on a private house. I know itâ€™s common on prefab council houses, but not sure on cavity construction, and how it would work with downpipes, window openings etc. I think this is where the costs will creep up - way above the costs of the actual product . i.e. in Labour, so is ti possible to fit on a DIY basis? Or even take the installers course and then do it myself?

Loft
Top up to 300mm with warmcell. But, how can I keep the space for storage? Use I beams laid at a cross to the current joists? Use kingspan insulated flooring boards?

Windows.
Currently uPVC standard glass double glazing. Consider adding a secondary glazing pane (to make it triple) with a low-E pane or I could try the stick on Low E film.

Is it possible to retrofit cavity closers or is the work involved not worth the effort?

Flat roof extension. :-(
Built in the mid 60â€™s so guessing it has no insulation. This either requires the mess of insulating from inside and finding a way to fill with warmcell, or going outside, and having a new warm roof construction built. (Maybe topped with grass?) Alternatively â€“ would it be cheaper to go with a new pitched roof?

This really onlly leaves draft to sort. I'll be taking out the 60's gas fire chimney, and replacing either with a sealed flue wood burner, or nothing. Need to convince myself on wood yet, but it may make a nice feature - even if it's never used. Adn would provide a backup if the leccy is ever off.

Hopefully having done all that, Iâ€™ll be left with a house that needs less than 5kw when itâ€™s freezing outside. Rather than the current 20kW it takes now. You should see the size of the radiators something that made me think theyâ€™d be ideal to run with a heat pump â€“ but thatâ€™s another story.

Is anyone aware of any software (free!) that lets you model your house? Something thatâ€™s a bit better than playing with spreadsheets and can let me input costs of each method to work out cost effectiveness. Or do I need to get a SAP expert in. I should add â€“ Iâ€™m an Accredited Domestic Energy Assessor (donâ€™t start!) â€“ but the software we use it too limited do this kind of â€œwhat ifâ€ analysis I need. It doesnâ€™t let you enter your own U values, and doesnâ€™t have any specific costing â€“ other than an average amount for each type of thing you can do. Hence why itâ€™s called â€œReduced Dataâ€ SAP. RDSAP for short.

Cheers

Simon

wood burning

ciderman — Tue, 14 Aug 2007 22:09:24 +0100

i feel that there are a lot of eco warriors who would have us all wearing rabbit skins and living off grass, and, at at ambient temperatures. come on, think a little, manage your own environment and look to your neighbours.
we can others can't. work from home- reduce your mileage-take a drop in salary. sadly, most will not do that.
oh dear , i could go on........

Pex tubing safe for drinking water?

scotts66 — Tue, 18 Sep 2007 23:39:43 +0100

I am wondering about the safety of polyethylene. Looking to get new plumbing installed in my home and my plumber recommends using Wirsbo Pex tubing over traditional copper pipes because of the difference in cost. Existing pipes are iron. Some may know that Pex tubing is made from cross-linked polyethylene and meets code for potable water plumbing applications. I wonder if the material may leach into the water though.

Any information/expierience with this product would be helpful.

Rounded Developments looking for board members

sallyh — Sun, 29 Jul 2007 18:37:23 +0100

Rounded Developments Enterprises is a not-for-profit company based in Cardiff that is dedicated to developing Sustainable Building in Wales.

They are a small organisation at present, but have big ideas and want to develop the capacity of the organisation to deliver them. They are looking to widen the set of skills and experiences within the board. There are currently six members on the board but we wish to increase this to about 10 in due course. Our structure is very flexible and dynamic and this enables us to respond quickly to demands and provide flexible delivery.

They have a number of very promising projects in the pipeline inc. the development of an Innovation Park in Cardiff (in partnership with BRE and a local charity) and are a partner in developing new unfired cementitious bricks and blocks with the University of Glamorgan. They also provide goods and services in support of sustainable building (we run a small shop and provide consultation services) from our Sustainable Building Centre in Splott, Cardiff.

They are looking for committed people with the skills, vision and enthusiasm to make sustainable building happen for all; from the DIYer to the mainstream builder. We are especially interested in people from: construction trades and professions; training and education; finance; research; and social enterprises.

If you know of anyone who might be interested in becoming involved they would appreciate a call. If you yourself cannot provide time maybe you have networks that can be contacted in order to spread this request to a wider audience.

Please visit their website in order to gain a bit more information about RDE and what it is doing. http://www.rounded-developments.org.uk
Tel 029 2040 3399

Cavity Wall Insulation AND Foam-backed blocks?

yorkshirerob — Mon, 17 Sep 2007 20:08:40 +0100

Does anyone know if it's normal practice to require BOTH foam-backed breeze blocks on the inner wall AND cavity wall insulation?
More to the point is there any problem with the combination?
Can't find answer anywhere - getting different stories from builder/plumber/wall insulation company !!
:cry:

Insulation under suspended floors

OIMO — Thu, 30 Aug 2007 07:07:04 +0100

Our plans to move house and undertake a significant green re-modeling of the new property have fallen through. So we are fixing our current abode ready for the winter!

We have decided to top up our loft insulation and also insulate under the two reception room suspended floors. The front reception room is above a cellar that is typically in the temperature range 8C-12C and has two grilled ventilation 'windows'. The positive side of this is that access from below is available, however the ceiling of the cellar is lath and plaster and damaged in some places and sagging in others. I suspect the easiest way to do this would be remove the lath and plaster, insert some mineral wool batts and replace the ceiling with a plaster board of some sort, perhaps a damp tolerant one? However I am not keen on mineral wool so can anyone suggest an alternative solution?

The second reception room also has a cellar beneath it with three ventilation bricks into it, however the access has been bricked up so access from beneath the floor is not an option. Also before this cellar was sealed they nailed a canvas under all of the floor presumably to try and reduce drafts (with only limited success I have to say). Rather than take up all the original floorboards is it possible to drill each one and blow some insulation in on top of the canvas?

In both of these situations I expect the insulation will come into contact with the walls at each end of the joists, so will damp be an issue and if so does that rule out most of the 'natural' insulations?

VAT on Green 'garden room'

Nick Parsons — Wed, 12 Sep 2007 16:51:47 +0100

I have put this in the housing category, but part of the problem is that it isn't considered as such.

I am about to build an architect-designed highly-spec'd timber-framed Garden Room for a client. It's only 15+ sq m, and to all intents and purposes it is another room to the house - it just happens to be 3m away. HMRC advise me as follows:

"....from the details provided, I can advise you that the relevant
information can be found in public notice 708 which deals with various
aspects for VAT purposes of building and construction. Therefore, see
comprehensive guidance at section 3 for the basic conditions when a new
building is being constructed.

Furthermore, you will note that although this will be a new build, it
does not meet any of the specific criteria at paragraph 3.2.1 to qualify
for the zero rate. In fact, because it is designed to be a separate
building from the main dwelling, despite increasing the living area, it
falls under the examples at paragraph 3.2.2 of the same notice.
Therefore, if this project does not meet any other criteria, all labour
and materials will be liable to VAT at the relevant rate. Additionally,
VAT would only be recoverable under the DIY builders and converters
scheme as per public notice 719..." (....which states that as it's not a relevant domestic building - a house - it's not eligible for the scheme! So my client has to pay VAT on the lot.

Any thoughts, comments, experience, anecdotal evidence?

Thanks,

Nick

BFF Spring 2007

GBP-Keith — Sun, 16 Sep 2007 19:20:01 +0100

Free PDF's online now for the spring edition (bottom of page).

This may be the last of the free pdf's as we are thinking of introducing an online subscription.

http://www.buildingforafuture.co.uk/spring07/index.php

I'm looking for about 20 volunteers to test an online version and comment. Send me an e-mail if you are interested please.

PS. Don't panic if you are a subscriber because the latest Green building mag is coming out in the post on about 20th September. About ten days late as we have changed our printer so fingers crossed.

Zero carbon versus carbon neutral

fostertom — Thu, 13 Sep 2007 15:20:27 +0100

Cosy racket:
"I think there is some confusion amongst the public about the difference between 'carbon neutral' and 'zero carbon'." continues John ...............
http://i30.photobucket.com/albums/c301/fostertom/Millwoodcarbon-neutral.jpg
"To achieve carbon neutral status, all Coppice Mews homes will be assessed by The Carbon Neutral Company to determine their carbon footprint. Investment in sustainable projects, such as wind farms, will then offset their annual carbon emissions. MilIwood Homes will ensure that construction is carbon neutral and will then buy â€˜carbon creditsâ€™ for the first year after the buyer moves in, offering purchasers the option to carry on the good work for life."

Should we all live in Travel Lodges?

tony — Fri, 14 Sep 2007 12:52:59 +0100

It is a clear winner on cost grounds! but what about in green terms? Do the pluses outweigh the minuses?

Belt and Braces -- examples of wastefulness

tony — Sun, 16 Sep 2007 09:22:22 +0100

Sorry guys I messed up the Title line of this one so am repeating it

Tony said,
In the days when we first started to use wire ropes for lifting loads we used to pass the rope through an eye or cleat and fix it back to itself with a wire rope grip (a u-bolt with a flange) The trailing free end of the rope would be tied onto the rope to keep it out of the way. This worked well but after a couple of mishaps where the u-bolts were not inspected and they either were damaged or worked loose through overloading it was decided to use two wire rope grips should be used in case one failed between inspections. No problems ever occurred but someone eventually decided that three would be better than two and this was common safe practice for many years. That was until some safety manager in an office saw a picture and thought that we should halve the risk by using SIX; this became law!

How much of this kind of thinking is wasteful of resources without adding benefit?
____________________________________________________________________________________________
Rimu Homes replied,
Loads and loads and loads,

I just got off the phone with our engineer to tell him we can't source C24 219 x 44 at short notice, in the lengths he specified for a project. I asked if we can use 219 x 38 instead and he said that would be fine. I can't remember how many times I have had similar conversations over the years. Usually with engineers.

The term 'over-engineered' is a pet hate of mine as engineering is about accuracy. In my opinion if an engineer feels he has to over specify he should consider a different career.
The culture of over ordering of materials is another pet hate.
_____________________________________________________________________________
biff came in with:

3

Mathematician: the integer greater than 2 and less than 4

Physicist: a value greater than 2.5 and less than or equal to 3.5

Engineer: three's three but we'll call it ten to be on the safe side.
__________________________________________________________________________________________--
Chris Wardle quoted
I'm afraid it is a sign if times. Everyone is so worried about getting sued that they err on the side of caution every time.

What I think engineers, building inspectors etc overlook is the fact that the manufacturers and the people who write the standards that we all work to have already allowed for a margin of safety so there is no need to add your own on top.

As for the Health and Safety fascists, with that lot it is all about having a piece of paper to say you have considered the risks etc. They never check whether policies are being implemented until someone comes a cropper, then the finger pointing starts and new legislation follows.

I'd like to live in a country where you are allowed to take a few risks and you live with the consequences of your actions. Make all these regulations into guidance that you can choose to follow or not. Most people do the right thing anyway, unless the "right thing" is an affront to common sense, and those that don't ignore regulations in any case. They serve no purpose other than to reduce the productivity of the economy.

Damp-proofing

marionhaste — Mon, 19 Mar 2007 19:26:52 +0000

We own a house which has been built into a hillside, so the basement has one external wall and three walls partially or wholly cut out of the slope.

The previous owners 'tanked' the room using polythene sheeting as a membrane then plasterboard built on a wooden frame.

Inevitably, there is damp coming through - black mildew, by the looks of it. We think the membrane is partially to blame for this, as the brick retaining wall behind it cannot 'breathe'. Indeed, since we made a hole in the membrane, the smell of damp appears to have reduced.

Do forum members have any suggestions as to how we could deal with this in an eco-friendly way?

Apologies if this has been discussed before - I did try to plough through the old forum, but couldn't find anything relevant. Any advice very gratefully received.

Marion

Fascinating history of the Vapour Barrier + construction idea

tomsusweb — Sun, 02 Sep 2007 20:53:10 +0100

I just found this very interesting article:

http://www.housebuildersupdate.co.uk/2007/07/little-known-history-of-vapour-barrier.html

I'd be interested in forum members thoughts - especially as there still seems to be a lot of debate on this forum about breathing wall timber frame construction as described in the Whole House Book and advocated by Warmcel. (e.g. see here: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=532&page=2 )

I'm about to embark on a self funded new build in Ireland. Building control and codes are a non-issue for me, so I'm contemplating something radical. A timber frame house with electric fan assisted passive stack ventilation to remove moisture laden air from all rooms. Wall construction (inside to out): sasmox boards on 6x2 studs with sheeps wool insulation, then 100mm tektalan e21 magnesite wood wool insulation boards and then a render of waterproof rein fibre cement on a mesh (rein fibres and mesh will prevent cracking).

Conventional wisdom says this is madness.

My logic suggests that it will be super insulated, the studs will be warm - hence no due point on them, and internal most moisture will be moved by the ventilation. Obviously I will need to carefully keep an eye on the rein fibre render, but unless water is pouring in from the outside, the timber is 100mm away and should be safe. The advantages of taking this route are simplicity, cost effectiveness and super insulation. The danger according to conventional wisdom is that the timber will rot. I don't think it will.

More info on tektalan insulation boards is here:

http://www.skanda-uk.com/heraklithProducts.htm

More info on Rein fibre cement which I have used in a 7mm coat to create waterproof bird baths that haven't cracked in years:

http://www.koicymru.co.uk/const9c.htm

http://koicymru.co.uk/q&a7.htm

I'm almost tempted to try the construction as an experiment. The thoughts of the forum are very welcome!

(This is my first post - I've been a long time lurker - many thanks for all the insights on the forums.)

A Life Without Renewables

Neil Adam Hall — Mon, 10 Sep 2007 15:16:28 +0100

I am a little apprehensive with regard to renewable energy technologies, the first step in housing design surely is to: a) reduce the need for energy and b) to use energy more efficiently in the building; before energy is to be supplied from renewable sources.

Cyril Sweett's 'Cost Review of the Code for Sustainable Homes' tells us that CSH minimum performance standard for energy efficiency at Level 3 is achievable [under certain dwelling types] without the need to integrate renewable energy technology into house design. However there is the need to integrate WHMVS into the design.

Assume a property were to be built which would not be affected by the Merton Rule or FALP, etc... and therefore would not require renewable energy technologies to displace a % of the dwellings CO2 emission rating.

Is it practical to expect a building to meet CSH Level 3 energy efficiency standard without the need to integrate renewable energy technologies into the building design? What U-values [walls, floor, roof and windows] and level of air tightness would be required in order to achieve this?

And is achieving CSH Level 3 energy efficiency standard without renewables a cost effective option? Or should we forget thermal efficiency and install oversized boimass boiler's in every house to meet these Code requirements?