I have a question for the people who know some stuff about roofs.
I recently bought an old house and I want to insulate the roof. Currently it's just asbestos slates over the wooden frame and the bedrooms are right beneath it(so our attic is actually just our 1st floor) because of wich I can't insulate from within(bricked walls supporting the wood, can't get behind it).
I wanted to insulate from the outside with hard PIR insulation plates(Where I live this is called the "sarking" method). Problem is I have a very steep roof and the asbestos slates wich have to be removed. Not easy to work on it and chance of sudden rain....
So I was wondering, how bad would it be to just work over the asbestos and put down the insulation and new slates over it? Encapsulating it kind off. I asked a roofer and he said he didn't really see a problem with it. But that's one guy, I want to hear from you guys what you think about the idea.
The wood itself is quite strong, a few roofing companies looked at it(small attic, about 1.4m high) and said that it was in great shape and we could even use rooftiles wich are off course a lot heavier then slates. So I was thinking, just leave the old roof and put a new one on top off it? They do the same thing with outside insulation ...
Pic related, my house.
I didn't understand much of any of that apart from the asbestos...if it's possible to have it removed and you plan on staying at the location, I'd remove it.
>>961866
https://www.youtube.com/watch?v=hm4Nx8N--Ls
This kind of shows how it's supposed to be done.
Except we wouldn't remove the old slates, just leave them there.
Asbestos causes harm when small particles are released, of wich we'll have a lot more of we have to remove every slate.
Pic is how the roof looks like from inside.
>>961877
I'd probably just sprayfoam that. Seems like a pretty big hassle any other way.
>>961877
Not sure why you'd want to leave the old asbestos tiles there. Just leaving a mess for someone else to clean up later.
Do it once, do it right.
>>961894
>Do it once, do it right.
What's that saying? Not enough time to do it right but always time to do it twice? Something like that. Basically cutting corners often takes longer and ends up being more expensive in the long run.
>>961880
Yeah the problem is we can only do the top, sides of the rooms are behind brick walls, already talked with/showed to an insulation guy, did said it's best to just isolate from the outside.
>>961894
> Not sure why you'd want to leave the old asbestos tiles there.
Removing costs money because you need to rent special dumpsters etc. Also takes more time and it's quite a dangerous roof already to work on with the steep incline. Also the risk of waterdamage.
>>961919
I don't see how less work is more expensive.
Ignore these guys thinking asbestos is like nuclear waste. Its not.
That roof has been on there and doing its job well, and I'm willing to bet it probably has a couple decades left in it as is.
Your roofer isn't steering you wrong; putting a new roof over the asbestos roof isn't a bad idea because you'll essentially have 2 rooftops after the insulation is installed, adding to the weatherproofing.
Asbestos is in probably every house built before 1985. Its probably in the drywall and mud. Many houses built before 1980 probably have asbestos in the mastic and vinyl tile. Most contractors will agree, if there isn't a need to disturb or remove it, leave the asbestos there. Its a decent vapor barrier, its good insulation, it holds other materials together. Its very common for new floors including wood, tile and carpet to simply be installed over asbestos tile flooring.
It costs a shitload to remove it and dispose of it properly. Often it will cost as much to remove it as it will to simply build over it.
>>961877
Friable is the word you're looking for. Asbesos is a friable material and is only dangerous when the material has been disturbed and dispersed into the air. When old asbestos drywall is removed, they saw with a sponge to wet the powder and dust and get it down out of the air.
I assume that picture is your attic, why can you not insulate in there, either blown in or regular batting?
>>962081
Yeah the slates arn't that friable, they're quite hard, luckily that means I can remove them myself without needing a special contractor.
>I assume that picture is your attic, why can you not insulate in there, either blown in or regular batting?
See pic related, I can do the top(still difficult, there's almost no room to move except for the middle part of the roof that you see in this pic) but the sides would still not be isolated.
I did alot of research/asking around about this and everybody says Sarking is the best way to go because I'll be able to create 1 big solid piece of isolation without any cold bridges and working inside the crawlspace is almost impossible, especially at the 3 dormers.
I would work from the inside if I could but the brick walls are supporting the roof(I'm guessing) and I don't want to risk any structural problems tearing them down.
Also, after having done the roof I'm also going to put the same kind of plates on the outside walls and connect them to the roof insulation creating 1 big insulated bunker if you will.
> Its a decent vapor barrier
Yeah I was wondering, if I leave the asbestos slate and add 18cm PIR (already bought the plates), do I still need a Vapor proof barrier in between. I can't find any solid info about vapor and PIR, only people disucssing it on forums ....
>>962191
As far as insulating the dead space to the left and right of the bedroom walls, you may have to punch holes in the walls to get some insulation in there. The added insulation will pay for itself and any drywall or plaster repairs you'll have to do over the next few years.
As far as the vapor barrier, I would add the additional layer, its not water tight and blocking all vapor, plus additional moisture protection is still a pretty good thing. Just be sure your roofer is aware of what you're insulating so he know about the attic breathing qualities. That is, the ventilation and airflow up there to prevent your bedroom from becoming an oven in the summer. You still want 90 degree hot air blowing around in there, because the attic temps are far higher than that.
The long and the short is leave the asbestos tile in place, insulate where you can and maintain proper airflow in the attic and roof areas.
>>962430
> you may have to punch holes in the walls to get some insulation
Yeah I know but the guy from the insulation company who do this kind of thing just said it's not worth the hassle and to just use sarking. I think 18cm of solid PIR plates will be plenty of insulation no? Problem was that it's too difficult to fill it up properly he said .... It's a wall like 1.5m high
>>961861
Roofing contractor here.
best method you can tackle your situation with is installing pink roll fiberglass insulation.
dont ever fucking sprayfoam anything. if it deteriorates or you ever want to remove it, its a huge pain in the ass and will be incredibly expensive for what you're getting. the shit doesnt come up clean ever.
>>962831
That expanding foam "insulation" and sealant is garbage, but would you recommend blown-in poly-fill insulation for OPs application?
Hydrantenschild.
germanfag?
