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I've been following the threads on insulation although am still in a state of confusion / learning. I have 3 external 600mm stone walls in this room and previously they have had no insulation, a very poor vapour barrier (some polythene some roofing felt) and very draughty tongue and groove nailed on top to the wall batons. The floor has been cracked open at one time and a damp membrane installed which runs 50cms up the walls.
I would like to lime render the gable wall (one with the fireplace - fitting a stove) leaving a few stones exposed but want to insulate the other 2 external walls and the ceiling.
Is it possible to integrate a lime rendered external wall into 2 insulated walls? Anybody got any experience of this?
Yes, i know that it would be much easier to dryline entire room, but i would really like to have the gable end just lime rendered. Don't have much room to play with and external insulation not feasible. Cheers Alan
Why cant you ask us a nice easy question! My advice as you will know is to do external insulation.
If you insulate internally you could very well regret not doing all three walls the same. What you propose will most likely work but the end wall will be high heat loss and cold, cold will bridge in round the corners of the room too. The ceiling should be straight forward to insulate so please dont show us any photos of up there...
At least 75mm or upward of Hemcrete is as far as I'm concerned the only way to insulate internally. As it's 5yrs since last time I was obliged to specify internal insulation, and a lot has changed since then, I can't say I've yet had experience of the Hemcrete solution. But at all cost I'd avoid ending up with a lightweight internal wall face, as by drylining. Don't!
Mmmh! The cottage has very little room at the front as it is on the edge of the road and its in a conservation area, (row of fishermans' cottages) so external not very practical. It will not be heated every day so very little benefit from thermal mass, so thats why i'd like to insulate. However, i would like to keep some character. I have been looking at Hemcrete, but not sure about how easy it would be to apply DIY style, unless you know of anyone in NE Scotland who can do the spray job?
I guess the issue may be cold spots / condensing / moulds - you can internally insulate those walls no problem (many threads on that here), but the issue will be that you have one 'cold' wall - potentially creating an area of higher moisture (condensing). This would be exacerbated by having the other two walls 'sealed plastic bags', and one wall nice breathable lime....
On top of that you would 'degrade' the value of the insulation on the two insulated walls because of the cold bridges at corners as Tony says.
How about some 'fake' stone work in places, on top of some insulation if you want some character? ;-)
Apologies for what might be a very novice question but I am new to this site. I have a ca. 1900 built house, with a basement (recently tanked) whose external walls are constructed of two brick skins with a cavity in between.
I wish to put in cavity wall insulation but am concerned about damp (does the age of the property and the presence of a basement complicate this?) and also my wife suffers from a lot of allergies/chemical intolerances so I would need to use something very inert.
How about spray foam insulation? This process is done on steel hulled yachts before the internals are added. My pal did this approach to his barn conversion several years ago. The house it well insulated as a result and almost air tight. It took some serious convincing of the local building control officer to get agreement. It would be easier now due to the availablity of the approved inspector route instead of local authority. After the foam is applied (typically two inch of polyeurathane) the foam is plastered in the conventional way. This technique will preserve the feel of the old house as the foam expands on application and gives you the look of plaster applied direct to the stone below
Alant, Try this http://www.aerogel.com/markets/c_house.html Similar construction to yours although in Switzerland. The fleece drapes easily over existing contours (you could cut holes to expose stonework here and there) tucks into and around reveals. Could you detail it to go around the gable wall ends and onto the return walls? Also Aerogel is vapour permeable "breathable" so perfect to use with lime based renders. The client used a similar but not so heavy system internally on some of the other outside walls.
Very interesting Saint! Its good to see some case studies, it gives you a bit more faith in some products. I didn't realise this stuff was breathable and they seem to have some dealer in Scotland. I must investigate how to attache it and how easy it is to lime render over.
I have been trying to find out about Hemcrete, but can't seem to find any positive leads.
Gotanewlife, Yes website is a little thin on technical performance but judging by description 40mm would equate to about 8-10mm "ordinary" reasonable insulation?
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