Tiling on concrete floors

[Terry Everall]

Not an expert on time to allow concrete to cure before you should tile

Any info?

[Mark (smokey mow)]

Is this just the screed on top or an unscreeded concrete floor slab? and does it have underfloor heating?

[Gromit]

Normally allow 1 day per mm of concrete/screed to cure and dry as a guide. If its concrete we normally say at least 28 days before you can lay stuff onto it.

[Terry Everall]

Its 100 mm of concrete over 150 kingspan floor insulation

One room has underfloor heating and other doesnt and both floors will be tiled ASAP!!!!!!!!!!!!!!!!!!!!!!!!

[Mark (smokey mow)]

For a 4" concrete floor you should be looking at around 6weeks before tiling etc.  but you need to allow at least twice that time before turning on the underfloor heating.

[carpetstu]

^^^^^^^ what he said. If you put any type of floor covering in before this you are asking for heaps of problems.

Drying time takes longer in winter due to humidity levels. Don't be tempted to do it until it's properly dry. And just because the surface  looks dry doesn't mean the moisture level below is the same!

Edit to add - tile adhesive where underfloor heating is needs to be resistant to the thermal levels.

[Terry Everall]

Can extra convector heaters help dry it out and reduce timescale?

[Gromit]

Can extra convector heaters help dry it out and reduce timescale?

If you force dry concrete it`ll end up brittle and crack. You have to leave it to dry/cure at its own pace. The longer you keep concrete wet, the stronger it ends up. Not what you want to hear but if you dont want problems down the line, it`s the only way.

[carpetstu]

One thing that can help is on dry days open the windows \ doors and blow cold air across the floor with a desk fan or similar. Do not leave the windows open on damp days or evenings though as this will allow damp in!

[Hammy]

I recall when our conservatory was put up; the supplier would not put the laminate floor down for 6 weeks

[Bryan C]

Repeat

^^^^^^^ what he said. If you put any type of floor covering in before this you are asking for heaps of problems.

Assume you've got a dpm so the moisture can only travel upwards to get out.

Convectors don't help cos you've got to draw water from the bottom regions of a dense 4" slab through to the top. There is a risk that you might make the top surface of teh slab dusty too - not good for adhesives, and can you be sure its dry all over.

I have worked with contractors who have used a specialist membrane laid on top of the slab before tiling but they are very expensive and probably used where they want some insurance that all the water has dried out even after leaving  the drying out time. In those situations they risk huge claims if somebody has moved in and then got to move out again cos the floor tiling is peeling up.

No chum - patiece is a virtue. Do something else for the 3 months that its drying out - perhaps upgrade the Westie or decorate, but  don't put vinyl down yet.

Stay Cool

BryanC

[Mark Stanton]

some wise words and top advice Mr E          

[carpetstu]

I recall when our conservatory was put up; the supplier would not put the laminate floor down for 6 weeks

That must have been a dry spell in the summer that the conservatory was built?  It would have been 12 weeks in Autumn / Winter .

[Terry Everall]

Trouble is that the boss (SWMBO) cat believe that the new sun room cant be used until tiled approx 3 months after being finished. Bulider not too please either as stage payment is after "completion"

Them TV progs that do speedy makeovers seem to ignore any rules!

[John Loudon - Sponsorship Liaison]

She will have to wait Terry. Surely the builder will know what to do if he's any good.

BTW - what use a sun room in the winter?