I'd be very grateful for any advice on my flooring project. I've read lots of threads on several websites but I'm still not sure which approach is best for me.
I've bought 1800x120x20mm oak engineered structural floorboards, with 6mm oak top layer, T&G on all four sides, to refloor two reception rooms each about 4m by 4.5m linked by a double doorway.
I chose these because they can be laid directly onto joists with no subfloor. But now I don't know whether to do that, or lay a plywood(?) subfloor first then float the boards on top.
The joists in one room are ancient hardwood (oak?), fairly flat, just propped up on bits of stone (its a very old house!), not fixed to anything but the floorboards. Joist spacing varies 35-50cm, they can be moved easily if boards are removed. Unfortunately the old wide pine floorboards on top are wormeaten, bowed, and much hacked up in the past to install pipes and cables. I'm planning to get rid of these old boards.
The other room has modern softwood joists (about 35cm spacing) and softwood boards, some of which I've already removed to install CH pipes. This floor is too springy, so I need to add joist supports, more of the boards need to come up to do this. I also need to find and block some mouse holes under the floor, so I'm going to end up ripping up all the boards anyway to find these. These boards are nailed down, the only way I know to get them up in a reasonable time is the destructive approach!
So assuming I'm getting rid of the existing floorboards, my main question is: should I fix my engineered oak boards direct to the joists, or lay a subfloor (plywood?) first?
If fixed to joists, I read that I can secret-nail them using something called a portanailer? I've also read about secret screwing using special screws, is this better than nailing? Should I also glue the boards together? Is it possible to include a vapour barrier, if so how? I have CH pipes running across joists in notches immediately below floor, this might make fixing difficult in places.
On the other hand, if I lay a subfloor, I believe I can install the oak boards "floating" with foam underlay? That sounds good, but it raises the floor level. Since I'm 2 inches taller than my doorways already, the lower the floor the better. Will 12mm ply do for the subfloor? Can I include a DPM? Is this likely to give a better result than fixing boards to joists?
I haven't done flooring before, except some idiot-proof lock-together laminate, so if there's a method that's easier to get right, that's what I'll go for.
Thanks for any advice.
I've bought 1800x120x20mm oak engineered structural floorboards, with 6mm oak top layer, T&G on all four sides, to refloor two reception rooms each about 4m by 4.5m linked by a double doorway.
I chose these because they can be laid directly onto joists with no subfloor. But now I don't know whether to do that, or lay a plywood(?) subfloor first then float the boards on top.
The joists in one room are ancient hardwood (oak?), fairly flat, just propped up on bits of stone (its a very old house!), not fixed to anything but the floorboards. Joist spacing varies 35-50cm, they can be moved easily if boards are removed. Unfortunately the old wide pine floorboards on top are wormeaten, bowed, and much hacked up in the past to install pipes and cables. I'm planning to get rid of these old boards.
The other room has modern softwood joists (about 35cm spacing) and softwood boards, some of which I've already removed to install CH pipes. This floor is too springy, so I need to add joist supports, more of the boards need to come up to do this. I also need to find and block some mouse holes under the floor, so I'm going to end up ripping up all the boards anyway to find these. These boards are nailed down, the only way I know to get them up in a reasonable time is the destructive approach!
So assuming I'm getting rid of the existing floorboards, my main question is: should I fix my engineered oak boards direct to the joists, or lay a subfloor (plywood?) first?
If fixed to joists, I read that I can secret-nail them using something called a portanailer? I've also read about secret screwing using special screws, is this better than nailing? Should I also glue the boards together? Is it possible to include a vapour barrier, if so how? I have CH pipes running across joists in notches immediately below floor, this might make fixing difficult in places.
On the other hand, if I lay a subfloor, I believe I can install the oak boards "floating" with foam underlay? That sounds good, but it raises the floor level. Since I'm 2 inches taller than my doorways already, the lower the floor the better. Will 12mm ply do for the subfloor? Can I include a DPM? Is this likely to give a better result than fixing boards to joists?
I haven't done flooring before, except some idiot-proof lock-together laminate, so if there's a method that's easier to get right, that's what I'll go for.
Thanks for any advice.
