Hi, I have a chalet style house with full width dormers on the font and rear. I have recently found out that neither dormer structure (front or rear) has any insulation; as such my house is extremely cold. So far I have draught proofed all windows and hung heavy curtains. My loft has been insulated as have the cavity walls - this leaves the dormers, I would like to insulate this space. Can anyone offer any suggestions as how best to do this, I'm aware that the "best" method would be to remove the interior skin of the dormer and filling with insulation, however this would effect all first floor rooms (4x beds, 1x family bath and 1x landing)?

I have the following thoughts:
- Is it worth cutting Celotex boards into rectangular strips and pushing into the dormer roof void, which I have access to from the loft?
- Could I hire the machine that is used for cavity wall insulation and use this to fill the dormer voids?


Any thoughts gratefully received.

Regards,

Chris

I think Tonys reference is excellent. One saving grace in your favour is that you will have a plasterboard ceiling and so it should be fairly easy to get the insulation to slip down the slope, though there could be some snags. Thinking aloud, I wonder if you could use some string with a heavy (lead?) weight on it, if it would slide down the slope, this string could then be used to tension or pull through your insulation.
Frank

Tony, Chuckey, Jeff B: Thanks for the posts.

I have looked through the thread and found some useful tips namely the insertion of the Celotex etc. into the ceiling of the dormer (although my dormers are rectangular/flat roofs and so there are no angled walls/roofs). My original post mentioned this but I wasn't clear on some of my concerns, i.e. if I install Celotext into the ceiling but it is NOT tightly fitting (due to the limted access) is this worth while or is this a waste of time/money?

Similar question as above, is it worth install insulation on the top of the dormer if I am unable to get insulation into the sides and the front of the dormers?

Jeff B - I'm afraid I'm not as lucky as you, I have very small rooms and so I cannot afford to loose any space.

Regards,

Chris

Thanks Tony.

My "house" is a contradiction in many respects, exceptionally well built brickwalls but comical wooden dormers, strips of carpet nailed to fence pannels in the garden (!!) but washing lines securely seated in 4ft of cement - all causing much amuzement (and some frustration).

As far as I can tell the dormers do not have any air/wind blowing into the voids, there are no air vents/gaps etc., I cannot hear any noise or feel much of a draught (when we had some of the plasterboard off). Also there is no moving air under the floorboards. I have no access to the the sides/front of the dormers.

I have broched the inject/blow into the dormer subject with a couple of contractors but they refused to undertake the work, I believe due to the high level of risk against the guarrentee that they offer, which is why I've been considering attempting the task myself.

It sounds like we're heading in the direction of "take the plasterboard off and do the job properly".

Regards,

Chris

Hello cereeve

As far as I can tell nearly all dormers are pretty comical in terms of insulation/construction. The walls of mine are tounge & groove pine with plaster & lath on the inside and lead on the outside. In terms of sorting mine out I've put a large contingency in my budget and put them inthe think about them in the summer box (which is when I will get to that part of the insulation project). Remove & replace seems the only option!

There probably is air movement in the voids around your dormers and under your floors (unless you are very lucky). Have a look at some of the airtightness threads. If you have a suspended wooden ground floor you would be astonished as to how much difference sealing & insulating this will make to your life.

After much thought we went for the 'take the plasterbaord off & do the job properly' approach principally because was the only way of ensuring that the insulation is going to work well. Doing it this way also deals with airtighness and also allowed close examination of the structure of our house (built in 1932).

All I would say is think long and hard before you start. There are a number of other jobs worth considering while you are tearing you house apart. In our case we decided to replace our lead/black rubber insulated heritage wiring and need also to completely replace the plumbing. Most important is to get your head around the concept of cold bridging and creating a warm (insulated) envelope with no unisulated areas. There are plenty of good websites (the insulation maufacturers have good pictorial guides as to how to best fit their stuff) and the green building guide is very usefull; a new version is due out early next year with a volume devoted to renovators.

S.