floor flex

[quick draw macgraw]

Hi All,

Any suggestions how to best support this floorboard where it meets the concrete as there is no joist at the point of meet and as i,m overlaying with 6mm backer still be too much flex.
Was thinking of wedging some 3x2 up to underside and screwing down.

cheers Steve.

[howard]

what about expansion foam ?

[quick draw macgraw]

never used it mate but dont think i'd be confident using it.

[Sir Ramic]

how deep is the void? woould you not be better using sand and cement?
Cut back the over hanging boards and fill the gap. i would put an expansion joint in anyway where the 2 meet.

[howard]

Ive seen it used in the same situation on site there was no movement after and it lasts for years

[quick draw macgraw]

Didn't actually measure the void as that option didn't occur to me will prob have another look to see if its viable. Aware of the expansion joint thanks.

Steve.

[quick draw macgraw]

If the sand cement option was took where would the expansion joint go? where boards meet sand,cement. But what about where sand cement meets concrete?

[Sir Ramic]

Where the wood and screed meets. Never had a problem where screed meets screed before. What method are you using to fix. Overboarding ,Ditra?

[grahamster]

i would go with sand & cement,with a few bricks to fill in most of the gap.then top of with more sand & cement.

[quick draw macgraw]

Because of the height difference was going to use 6mm backer boards on the wood.

[grumpygrouter]

Is it practical to lift the boards and secure timber to the concrete to fix the boards to?

Grumpy

[Dave]

Lift the boards up....insert damp proof membrane and fill void with rapid setting concrete mix...once dry relay the boards and fix the boards to the new concrete to support the edges......then just insert the movement joint at the end of the boards..........