Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

Buy individually or both books together. Delivery is free!


widget @ surfing-waves.com




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




    • CommentAuthorandyman99
    • CommentTimeNov 9th 2017 edited
     
    We are considering making an offer for a chalet bungalow that was apparently built 20 years ago. Guide price has morphed into a sealed bid auction, so I'm trying to understand likely improvement costs before jumping in.

    My main worry is heat loss through the bedrooms, I'm assuming limited insulation in the roof, would this be a safe bet assuming 1997 ish build date?

    To take the roof off is going to be a step too far based on what I'm expecting to have to offer to get the property.

    Can reasonable improvements be made to this type of construction from the inside? Rooms are fairly generous, so I think we incorporate some insulation without compromising the overall space.
    • CommentAuthorgravelld
    • CommentTimeNov 9th 2017
     
    *Possibly* crap air tightness between the ground floor/first floor too. Are there any inspection hatches you can look through?
    •  
      CommentAuthordjh
    • CommentTimeNov 9th 2017
     
    Posted By: andyman99We are considering making an offer for a chalet bungalow that was apparently built 20 years ago. Guide price has morphed into a sealed bid auction, so I'm trying to understand likely improvement costs before jumping in.

    My main worry is heat loss through the bedrooms, I'm assuming limited insulation in the roof, would this be a safe bet assuming 1997 ish build date?

    I'm no expert and would recommend getting a surveyor who knows his onions, but I seem to remember that period was infamous for scandals of properties built with insulation missing or not properly installed, so I'd be very careful.

    To take the roof off is going to be a step too far based on what I'm expecting to have to offer to get the property.

    Can reasonable improvements be made to this type of construction from the inside? Rooms are fairly generous, so I think we incorporate some insulation without compromising the overall space.

    It depends what you're aiming for, but its much easier to make improvements with external insulation rather than internal. On a chalet bungalow, I'd be looking at the floor insulation and the sloping roof ('skeiling') insulation as well as the roof and walls.
    • CommentAuthorJeff B
    • CommentTimeNov 9th 2017
     
    My chalet bungalow was also built in 1997. There is 3 inch Celotex insulation between the rafters behind the sloping ceilings and the dwarf walls. I found it is very easy to internally insulate the sloping ceilings and dwarf walls to improve the insulation. Less easy to insulate the voids between the bedroom floor joists - I simply blocked each end of the void with a rolled-up piece of insulation.
    •  
      CommentAuthorfostertom
    • CommentTimeNov 10th 2017 edited
     
    'Take the roof off' - you mean the tiling, not the whole roof structure?

    I'd recommend biting the bullet and doing it from above - 11 OSB3 gapfilling glued and screwed over the rafters, EPS EWI glued on over that, breather felt, downslope battens, tiling battens, tiles. At same time sort out the insulation between rafters - v easy from above, full fill thoroughly. If nom 100mm between, 150EPS over.

    The simplification and elimination of fiddling is worth a lot, and you end up with the classic 'teacosy' of insulation and airtightness giving abs max bang for buck.

    After pic:
      P1000256autocorrect med.JPG
    •  
      CommentAuthorfostertom
    • CommentTimeNov 10th 2017
     
    Before pic:
      2011-03-30 056.jpg
    • CommentAuthorandyman99
    • CommentTimeNov 10th 2017
     
    Thanks everyone for responding. Initially concentrating on an internal attack, although I appreciate this is probably not the best method.

    Posted By: Jeff BMy chalet bungalow was also built in 1997. There is 3 inch Celotex insulation between the rafters behind the sloping ceilings and the dwarf walls. I found it is very easy to internally insulate the sloping ceilings and dwarf walls to improve the insulation. Less easy to insulate the voids between the bedroom floor joists - I simply blocked each end of the void with a rolled-up piece of insulation.


    Jeff, very interested to know if the Celotex insulation was installed at build time or if you have added it subsequently?

    Posted By: gravelld*Possibly* crap air tightness between the ground floor/first floor too. Are there any inspection hatches you can look through?


    Visited for 2nd time yesterday, and we couldn’t find any way of getting under the skin of the building. Plenty of cupboards built in so it would be easy to do this but not without some level of destruction that might not be appreciated atm.
    • CommentAuthorgravelld
    • CommentTimeNov 10th 2017
     
    In Tom's pictures, it's the area beneath the first floor windows, where a triangular void is often formed, that the problem often is.

    Just an idea, now it's getting cold, do a drive-by with a thermal imaging camera? Won't be a massive temperature differential but still might see something...
    • CommentAuthorJeff B
    • CommentTimeNov 10th 2017
     
    Andyman99 - the Celotex was put in when the house was built. I just did the IWI stuff.

    We didn't have any cupboards built into the dwarf walls so it was relatively easy to crawl about in the triangular void spaces. I suppose you could put IWI inside the cupboards? Not ideal I guess. What I did was to cut some more access doors into the void spaces and boarded over the quilt insulation that is between the joists; this is used as a storage area i.e. is in the cold space, but for most purposes that's ok.
  1.  
    Our place is from about 150years earlier but the principle maybe similar for DIYing the roof bedrooms: lots of mineral wool above the ceilings. Remove the plaster from the sloping and vertical sections of wall. Fill the void above/ between downstairs ceiling joists with wool. Fit celotex or similar between the rafters/ studs, and more over them. Preserve ventilation gaps under eaves and beneath roof felt, but fill gaps visible round edges of downstairs plasterboard. Finish upstairs with new plasterboard, get plasterer to skim it if not confident yourself. More or less faff around the windows and bathroom.

    If you DIY then expect no more than couple of £k materials.

    Totally transformed the comfort and heating upstairs. Wish we had done ventilation at same time.
    • CommentAuthorJeff B
    • CommentTimeNov 10th 2017
     
    Will - totally agree with you regarding the transformation upstairs. The radiators are off virtually all year round as the temperature up there rarely drops below 17C, even in the depth of winter. I should add that we have five Vellux windows in the roof - three are large, about 1m x 1m, and two approx 1m x 0.4m. These are all real cold bridges - so all have been fitted with secondary glazing (my own design with twin wall polycarbonate glazing).

    I was a little bit disappointed with the situation during the summer. I assumed that all the extra insulation would reduce the amount of heat absorbed into the upper rooms, but the effect has been negligible.
    • CommentAuthorgyrogear
    • CommentTimeNov 10th 2017 edited
     
    Posted By: Jeff BThese are all real cold bridges - so all have been fitted with secondary glazing (my own design with twin wall polycarbonate glazing)


    thanks, this is a nice idea that I shall now pinch !
    (far better than my slab of XPS !).

    gg
    • CommentAuthorandyman99
    • CommentTime7 days ago edited
     
    Thanks everyone, I have a much better understanding now and happy that I should be able to have a good crack at improving matters should we get the opportunity.

    Other issue would be the ground floor, EPC says solid, limited insulation (assumed), well its certainly solid. Looking from the outside shows air vents. They are 13/14 courses down, so 1500 mm ish. Just wondering if this indicates a ventilated solid floor or if they could be just to ventilate the cavity. I know from last house that ventilated solid floor is about the worst case for heat loss.
      IMG_0161 (3).jpg
    • CommentAuthortony
    • CommentTime7 days ago
     
    Look like periscope vents to me, I reckon it will beam and block
    • CommentAuthorandyman99
    • CommentTime6 days ago
     
    Oh dear, but thanks Tony. Still wont put us off the house, but I fear another can of worms opening. Perhaps time to wait and see if we are successful or not before pursuing options.
  2.  
    If it is B&B with void, we're probably back to the 'Full-fill with EPS beads - yea or nay' discussion!
    • CommentAuthorgravelld
    • CommentTime6 days ago
     
    Seems to come round every three months or so!
    • CommentAuthorgyrogear
    • CommentTime6 days ago
     
    Posted By: Nick ParsonsIf it is B&B with void, we're probably back to the 'Full-fill with EPS beads


    or a conditioned crawlspace...

    gg
Add your comments

    Username Password
  • Format comments as
 
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press