Air tight, where is the info on this

Irish Steve

I have a 20 year old Dormer bungalow, and I know that there's no way it's even close to airtight, and we're paying for that big time.

I want to look at my options, they are going to be complicated, as the original build didn't put any insulation under the dormer section, so there's a huge area of the ground floor that has no insulation over it. I did a temporary partial solution by closing the gaps between the joists, but the long term solution is to make the entire place air tight so that we're not losing heat like crazy out through the roof area.

So, where do I find the regulations on air tightness so that I can do some reading and try and work out what the options for the roof are, with a view to getting things properly sorted.

It can't be too bad, but it needs to be better, when we get snow or frost on the roof, it doesn't melt that fast, in that we do have reasonable insulation in the accessible section of the joists, and up and over the dormer section, but I am still sure we are losing more heat that we should due to the absence of insulation under the dormer, and even with polystyrene blockers in the gaps, it's not airtight. Downlighters in the ceiling in the uninsulated areas don't help either.

Longer term, I'm also going to probably have to look more closely at the cavities, the walls are brick external, and 100mm block internal, with some insulation between them, but I am not overly confident that it was fitted that well, given some of the other issues that happened at the time,

Pointers to anything useful appreciated, in that we're also under huge pressure as our cash flow has gone to hell and back, so we're having to watch every cent, but doing something to the insulation may be one of those jobs that will pay for itself relatively quickly, as we're oil fired heating, which ain't cheap any more.

Thanks

MicktheMan

Unfortunately, dormers are notorious for air tightness weaknesses which are not easily (or cheaply) remedied.
The best solution may well be to change the roof from a cold to warm roof construction incorporating an air tight barrier. This will bring the current cold crawl spaces of the roof into the thermal envelope and completely change the thermal characteristics of the house for the better.
Probably not what you wanted to hear but if you want it "properly sorted" then you don't have many options.

Start by having the house pressure tested and take it from there.

Irish Steve

Mick,

I'd already come to the uncomfortable conclusion that changing the roof is my best (only realistic) bet, and I'm under no illusions how much work that's going to be, depending on the options.

There's not going to be much point doing an air test at the moment, it would be a lot of work to prove what I already know, the place leaks heat to beat the band at the moment, and I don't have money to spare right now.

The one advantage is that the roof trusses are pre made and have good depth on them, so it's not going to be too much hassle to put insulation between the rafters, the key issue is the changes from the old felt system that was used (badly) here, and the newer airtight concepts.

There's also the issue of the seal between the walls and the roof, and I'm expecting to have to do some work on external aspects of the roof, the fascias are not in good condition, so an upgrade to PVC will probably be part of the same exercise. Upgrading the insulation in the walls is also going to have to be looked at.

I guess I want to try and do as much research as I can before committing to an option, and more importantly, I want to make sure I know what I'm talking about before I get too involved, I've seen too many good ideas that didn't work, or were not correctly installed, or were the wrong option for the job, but the only option a particular supplier could offer. This whole aspect of energy conservation is still too new for comfort. I can still remember when Citizens band radios were first legal in the UK, there were any number of dealers set up to cash in on this new market, and a huge percentage of them didn't have a clue what they were selling, or if it was capable of doing what the user wanted, or even if it was legal, and certain aspects of the energy saving business look that way right now, hence my concern at doing my research before I get too deeply involved.

Cheers

Steve

sinnerboy

Irish Steve wrote: »

So, where do I find the regulations on air tightness so that I can do some reading and try and work out what the options for the roof are, with a view to getting things properly sorted.

Start here

MicktheMan

Irish Steve wrote: »

I'd already come to the uncomfortable conclusion that changing the roof is my best (only realistic) bet, and I'm under no illusions how much work that's going to be, depending on the options.

If you already know this then why doubt it? What I'm getting at is that there are probably no easy solutions to your problem and if your are truely interested in solving the problem once and for all then this is it. Btw, the previous statement is based on what you have posted and my practial experience of testing dormers and a proper survey/test would be needed to be done to be sure.

Irish Steve wrote: »

There's not going to be much point doing an air test at the moment, it would be a lot of work to prove what I already know, the place leaks heat to beat the band at the moment, and I don't have money to spare right now.

The air tightness tester should be able to advise you on your best options within your budget. That's what you're looking for, right?

Irish Steve wrote: »

The one advantage is that the roof trusses are pre made and have good depth on them, so it's not going to be too much hassle to put insulation between the rafters, the key issue is the changes from the old felt system that was used (badly) here, and the newer airtight concepts.

Generally, insulation does not do airtughtness and vice versa.

Irish Steve wrote: »

There's also the issue of the seal between the walls and the roof, and I'm expecting to have to do some work on external aspects of the roof, the fascias are not in good condition, so an upgrade to PVC will probably be part of the same exercise. Upgrading the insulation in the walls is also going to have to be looked at.

This seal should be part of the warm roof specification.
From my experience with dormers, you are loosing significantly more heat through the roof structure than your walls.

Irish Steve wrote: »

I guess I want to try and do as much research as I can before committing to an option, and more importantly, I want to make sure I know what I'm talking about before I get too involved, I've seen too many good ideas that didn't work, or were not correctly installed, or were the wrong option for the job, but the only option a particular supplier could offer. This whole aspect of energy conservation is still too new for comfort. I can still remember when Citizens band radios were first legal in the UK, there were any number of dealers set up to cash in on this new market, and a huge percentage of them didn't have a clue what they were selling, or if it was capable of doing what the user wanted, or even if it was legal, and certain aspects of the energy saving business look that way right now, hence my concern at doing my research before I get too deeply involved.

Not to me:).

Do-more

There was someone on here a few months ago who posted a lot of photos and details of the job they did on upgrading the roof insulation in their dormer.

I can't find it at the moment but perhaps you can or someone else can help, it will give you a good indication of what is involved.

goat2

i have been doing this with my dormer with the past month, it is hard work and alot of money, but worth it all,
i had to cut panels out of the sides of the rooms to get in crawl spaces, i got a fright when i saw what was going on in there, one big gale of wind, coming in where all the timber had been meeting the top of the wall, then there was the under floor draughts in upstairs bedrooms because of this, i used those cans of spray foam to seal off those places along with that white aeroboard to get that job done, also spray foam on top of wall between joists to block air there, then i blocked off air going to the slant on roof over bedrooms to try to get a coccoon, since then my house is far warmer, and i use about half the oil to heat house now

MicktheMan

goat2 wrote: »

i have been doing this with my dormer with the past month, it is hard work and alot of money, but worth it all,
i had to cut panels out of the sides of the rooms to get in crawl spaces, i got a fright when i saw what was going on in there, one big gale of wind, coming in where all the timber had been meeting the top of the wall, then there was the under floor draughts in upstairs bedrooms because of this, i used those cans of spray foam to seal off those places along with that white aeroboard to get that job done, also spray foam on top of wall between joists to block air there, then i blocked off air going to the slant on roof over bedrooms to try to get a coccoon, since then my house is far warmer, and i use about half the oil to heat house now

I hope, for your sake, you havent blocked all your roof's ventilation:eek:

goat2

MicktheMan wrote: »

I hope, for your sake, you havent blocked all your roof's ventilation:eek:

no i still feel the breeze, but not gale force anymore, as i do know that we do need some ventilation, but the way it was, i may as well have been living in a straw hut