Soldato
So I'm halfway through a garage conversion. We had a builder do the major works, laying foundations and bricking up the garage door and porch. Unfortunately he laid a floating floor without a damp proof membrane, just placed PIR insulation boards down with OSB on top.
Building control won't sign off without a DPM, so the plan is to lift the floor and insulation, lay a membrane, and rebuild the floor. The floating floor doesn't feel very solid so I would like to create something a bit more robust. The room will be a workshop so it needs to hold machinery etc.
Currently we have the original concrete garage floor around 120mm below the finished floor height in the hall. Then 55mm of insulation and 22mm board on top, so the garage floor is too low at present anyway. I plan to put in timber joists for a bit more strength, but there isn't the height for a proper suspended floor. In fact I can only realistically get 95mm/4" joists in!
So effectively, I think I'm trying to work out if a floor made of joists sitting on the solid ground will work. I'm at the mercy of how flat and level the concrete is (it wasn't perfect). I'm also not sure if the joists will act as a cold bridge where the current insulation doesn't. The garage is eminently warmer since bricking it over. In fact I've never felt it was cold in there despite having no heating yet.
Garage is about 2.8m x 5.3m. I was thinking to fix a stringer along the long walls and use joist hangers to fit joists between them. Then to maximise strength and compensate for the small timber height, use 3" joist widths and close spacing. And probably support them in the middle of the span somehow. But then they might be resting on the floor there anyway?
TBH I have more questions than answers at this point
I've booked some time off next week as I really need to push this forward, I'm paying £LOL to store my garage crap in a self storage unit.
Maybe I'm missing an obvious solution? Is a timber floor sitting on concrete just a terrible idea? Or am I overthinking it and I should just whack the joists in and shove PIR between them?
Building control won't sign off without a DPM, so the plan is to lift the floor and insulation, lay a membrane, and rebuild the floor. The floating floor doesn't feel very solid so I would like to create something a bit more robust. The room will be a workshop so it needs to hold machinery etc.
Currently we have the original concrete garage floor around 120mm below the finished floor height in the hall. Then 55mm of insulation and 22mm board on top, so the garage floor is too low at present anyway. I plan to put in timber joists for a bit more strength, but there isn't the height for a proper suspended floor. In fact I can only realistically get 95mm/4" joists in!
So effectively, I think I'm trying to work out if a floor made of joists sitting on the solid ground will work. I'm at the mercy of how flat and level the concrete is (it wasn't perfect). I'm also not sure if the joists will act as a cold bridge where the current insulation doesn't. The garage is eminently warmer since bricking it over. In fact I've never felt it was cold in there despite having no heating yet.
Garage is about 2.8m x 5.3m. I was thinking to fix a stringer along the long walls and use joist hangers to fit joists between them. Then to maximise strength and compensate for the small timber height, use 3" joist widths and close spacing. And probably support them in the middle of the span somehow. But then they might be resting on the floor there anyway?
TBH I have more questions than answers at this point
![Frown :( :(](/styles/default/xenforo/vbSmilies/Normal/frown.gif)
Maybe I'm missing an obvious solution? Is a timber floor sitting on concrete just a terrible idea? Or am I overthinking it and I should just whack the joists in and shove PIR between them?