Flooring into extension

Wigster

I'm planning a ground floor extension to make an open-plan living/dining area. Ideally, I want the flooring to continue seamlessly out of opening of the existing house and into the extension. The house floor is suspended timber, the extension is likely to be concrete. There will be either tiles or wood floor on top, all the way through (undecided as yet!).

How is a smooth transition between two types of floor achieved? Is it a simple case of getting the levels right? Will I need to rip out the existing suspended floor and pour concrete throughout?

Thanks in advance for any advice.

Wigster

ormus

yes just get the levels right.
you can certainly have a concrete floor to suspended floor join.

ive got two in my house.
(triple extension).

nicka99

our original house is suspended timber leading to a new extension with concrete floor and the floor runs straight through at the same level (although the extension is tiled vs laminate in the existing house). the builder will have to get the levels right to ensure they meet up correctly and work backwards to calculate to the bottom of the foundations. ours is 'beam and block' construction from the inner wall leaf with celotex insulation over then screed on top of that then finally tiled. There is a bit of leeway with the screed depth, tile thickness and the amount of tile adhesive if its coming up a bit short but if its too high then you'll just have to have a step up if its big or or fit a wide threshold that 'hides' the difference between the 2 levels if small.
I have a friend who ripped up all his suspended floor and concreted/screeded the lot underneath but that was because he was gutting the whole house and installing underfloor heating throughout. I dont think you want to do this just to match the new build if they dont meet up - that would be a huge job !

tpt

no problems with the levels. that should deffo be ok. BUT if tiling, be careful, if you have a concrete floor meeting a wooden floor, one will move, and one wont. you'll need some kind of movable joint at that point or another solution (there are several) to stop a crack forming.

its not too difficult - just be aware it needs consideration.

traineepensioner

If you're concreting up to a suspended timber floor make sure you don't block the airbricks and have sufficient ventilation or your existing joists will eventually rot.
If possible extend the ventilation using 100mm plastic pipes or add additional airbricks.

real1314

we had an extension and have a through-room. The extension was done and finished before I re-furbed the adjoining room (kitchen) so the floor levels are about 2-3mm different (lower in the extension). As I was too lazy to re-level the floors, I just laid my laminate flooring with the join running adjacent to the drop; so the joints accommodate the difference.

You can barely tell it's there, but it gives a good speed boost when sock-sliding on the lam. :cool: