Hi, its been some time since I last posted on this forum. Myself and my wife are looking to make insulating and/or airtightness improvements to certain areas of our house, I don’t think we can do everything in one go due to funds available. Is it worth getting some kind of survey done on the house to see what areas need improvement and what will give the most benefit? If yes how do I find the best person for this in my area?
The things we are considering doing are:-
Replace a south facing patio door that has a split pvc frame and is leaking air between the frame and wall.
Replace or repair the front PVC door, but it looks in good condition and doesn’t seal when shut.
Insulate an in roof area above the stairs, this causes cold draughts.
One I am unsure on, replace the 50mm cavity fibreglass insulation with modern material.
I might have more detailed questions on these subjects later.
It is impossible to decide this without a professional CWI survey. An independent one can be expensive and supplier ones are almost guaranteed to find problems that then need to be “fixed”.
I know one person that bought a house where the glass fibre had been compromised by ingress of water and frankly I wouldn’t go for glass fibre. But as you have it you should stick with it if it’s still in good condition. Look for flaws in the pointing, cracked bricks and imperfect junctions. If all looks well and you don’t live in an area with horizontal rain then you can rest easy. If not the wall faults need fixing and an independent survey would be a good idea.
One problem is that wet glass fibre is heavy and sags to the bottom of the cavity, compressing any good insulation in the process. Just topping up still leaves the bottom of the walls uninsulated (compromised).
I suggest insulating the whole roof to the same standard or all you do is move the heat loss elsewhere. While you are at it you need to consider a vapour barrier to stop condensation in the roof and a windwashing barrier to protect and enhance the insulation.
Is it worth getting some kind of survey done on the house to see what areas need improvement and what will give the most benefit?
Hi Steven,
I am a bit late to this thread but commenting on your question above, when we had a big refurb done the best money we spent was on a survey. It told us what could be done, what each was expected to cost, what benefits there would be, how the measures chained together etc.
We used Urbed. A good place to start now would be there or as Tim posted Routes to Retrofit who offered that service. It may not be worth the money if you only want to do a couple of things but on the other hand it may give ideas about things you had not thought of.
@Steven_Draper Well I do surveys/retrofit masterplanning which is my main area of work. Only worth doing really if you’re doing a deep retrofit where thought needs to go into all the joined-up activities and in what sequence. If you’re just doing one or two things then you could go for prescriptive LETI u-values and do the best you can piecemeal. But if doing more stuff, then a plan will help not just with u-values but also moisture risk, window schedule, thermal bridge modelling, coordinating design for the ventilation and heating system, helping find structural engineer if needed, putting together a work sequence list and so on.
Hi all thanks for your replies. Regarding topping up the cavity wall insulation, how is this achieved? is it injecting through the wall outside or applying from the top of the wall? Are there people that specialise in this sort of work? I enquired with one company off an official list of installers, they wanted to replace the old insulation with “new technology” so I was unsure if this was the best option.