Semi solid on concrete (again)

johnnyjb

Hi i know this might of been done a few times but i am looking for a bit of confirmation so i can finalize my situation.

Ive a semi solid floor coming Dont know the height , thickness but thats not a problem unless batons were being used. I wanna try to "float" it so im looking for ideas and what people have done in the past.

The concrete floor seems reasonably level so would i just use underlay , should i glue it etc.. Basically any tips from experience would be nice

Thanks

ronaldo84

if its a 15 or 18mm semi solid enginnered floor you can;
1) glue together and float over underlay
2)glue to the floor with a rubber elastic adhesive
3)lay 18mm ply or OSB board fixed to the concrete screed and porta nail(secret nail) the engineered floor to it.
i take it a concrete screed with insulation underneath. a 10-15 mm expansion gap is required around walls

slimjimmc

A lot of semi-solid is intended to be a floated, i.e. not fixed to the subfloor. You should always put down a plastic damp proof membrane (plastic sheet) and an underlay.

You need to make a few decisions:
- Which direction to lay the boards. Your choice depends on a number of factors such as will the flooring continue under the door into the next room/hallway, the position of windows (joints aren't quite as obvious if boards running lengthwise towards light source), shape of the room (square, rectangle) and any obstructions (your first row of boards should be placed along a long straight wall if possible).
- How do you intend to trim around fireplaces, under doors. Will you be fitting a door saddle, metal cover strip or wooden ramp. These may require you to leave extra gaps.

If the boards have a standard tongue and groove, ie. not a click system or clip system, then they must be glued to each other and clamped. Flooring strap clamps are handy for this, but you could use timber wedged against the opposite wall to keep pressure on while the glue sets.

Follow all instructions with the boards, especially flatness of the subfloor and size of the perimiter gap, usually 10-12mm. Watch out you don't let the gap get too small anywhere, including around radiator pipes, as this can restrict the natural expansion of the floor.

Spend a bit of time making sure the subfloor is well prepared according to the instructions. Make sure the sub-floor is spotless and free from pebbles and little protrusions which can pierce the plastic.

When laying the membrane overlap any joints by 300mm and seal with a waterproof tape. Allow the membrane come up the wall by about 100mm. This is to ensure that no part of the wooden floor will absorb dampness by direct contact with the subfloor or wall. The excess can be trimmed or hidden behind skirting when the the job is done. Don't forget to tape up any cuts made to get around pipes.

Get on your hands and knees and check the entire membrane for holes, tears or anything that might peirce it. Seal any holes and reinforce any potential holes with tape.

Use a board and a layer of underlay to mark the new floor height on the door. Do this with the door in the opened and closed positions in case the door isn't hung perfectly true. You can then decide if you need to trim the door or not, but remember the line is the finished floor level and you still need a small clearance gap under the door. Also consider any allowances you need to make if you're fitting a wooden ramp/joiner/saddle under the door.
It's handier to do this before you start flooring

Lay the underlay pependicular to the direction of the boards. 3mm foam underlay is cheap and popular, but softboard is good too and may give better insulation.

Check and double check all measurements before cutting, mistakes are easy to make but harder to fix.

Get kneepads!!! They're a must, you'll quickly be sorry if you don't.