Drying time 4 concrete

[dave100]

Dear All

Please could some advice the drying time for concete before tiles sholud be laid. Example only lets say in a conseratory floor.

Best regards

Dave-100

 

[White Room]

Depending the depth of the screed usualy 1mm per day, so 50mm would be about 7-8 weeks, you can go fast track with a decoupling membraine or green screed adhesive

 

[Ajax123]

Dear All

Please could some advice the drying time for concete before tiles sholud be laid. Example only lets say in a conseratory floor.

Best regards

Dave-100

If its screed then normally allow 1mm per day. If it's concrete it can be much slower cos the depth is normally more and the surface better sealed due to floating it up to a finish. There is also more water in it to start with. I would allow 2 days per mm for concrete. You could trap the moisture in with an Epoxy surface DPM or as Whitebeam says you can use a decoupling mat which will ultimately let the moisture dry out.

 

[dave100]

Thank-you both, for your advice and replies. Good too know you are all out there and happy and willing to share your years of knowledge with people.

Take care and keep on tiling

Dave-100

 

[bassman]

:welcome: to the forum :guitarist: lots of people here happy to pass on their experience

 

[White Room]

Hello and welcome as well

 

[faithhealer]

Welcome to our forums

 

[bighen]

:welcome::welcome::welcome::welcome:

 

[Olz]

:welcome: to TF

 

[DHTiling]

Hello and welcome......Good advice above will keep you right..

 

[Derry]

hi, welcome to the forums

 

[Terry Cottar]

25mm per week + a week under normal conditions. most screeds average 100-150mm so a 100mm screed is 5 weeks to be safe. if in doubt a good test is to take a porcelain tile and lay it on the screed leave it overnight if the tile has moisture on in the morning you cant tile if its dry you can

tel

 

[Ajax123]

25mm per week + a week under normal conditions. most screeds average 100-150mm so a 100mm screed is 5 weeks to be safe. if in doubt a good test is to take a porcelain tile and lay it on the screed leave it overnight if the tile has moisture on in the morning you cant tile if its dry you can

tel

Sand Cement screed will not dry at 25mm per week. The industry accepted rate is 1mm per day. 10omm is therefore closer to 10 weeks. Polymer Modified sand cement screeds dry faster due to less water. These are generally dry at 25mm per week. Some have specialised hydraulic binders which dry incredibly quickly similar to thin screeds and levellers. Anhydrite dries at the same rate as sand cement i.e. 1mm per day up to 40mm deep. Anything over 40mm deep add on 2days per mm i.e. 50mm is 60 days. Concrete takes much longer due to dry due to the depth, the fact that more water is present, the general pore structure and the surface finish. Of course all of these figures are dependent on the ambient conditions (normally 20oC and 60% RH) and no screed or concrete will start to dry till it stops getting wet. I like the porcelaine tile idea although not used it personally. I often advocate the polythene bag test. Place a poly bag on the screed and weight it down. Leave or 48 hours and then lift - if no moisture screed is usually dry but the proper test of course is to use a hair hygrometer.

 

[Terry Cottar]

Sand Cement screed will not dry at 25mm per week. The industry accepted rate is 1mm per day. 10omm is therefore closer to 10 weeks. Polymer Modified sand cement screeds dry faster due to less water. These are generally dry at 25mm per week. Some have specialised hydraulic binders which dry incredibly quickly similar to thin screeds and levellers. Anhydrite dries at the same rate as sand cement i.e. 1mm per day up to 40mm deep. Anything over 40mm deep add on 2days per mm i.e. 50mm is 60 days. Concrete takes much longer due to dry due to the depth, the fact that more water is present, the general pore structure and the surface finish. Of course all of these figures are dependent on the ambient conditions (normally 20oC and 60% RH) and no screed or concrete will start to dry till it stops getting wet. I like the porcelaine tile idea although not used it personally. I often advocate the polythene bag test. Place a poly bag on the screed and weight it down. Leave or 48 hours and then lift - if no moisture screed is usually dry but the proper test of course is to use a hair hygrometer.

most screeds are modded these days i cant think of anyone i know who would wait 5 months for a screed to dry out i think bal even reccommend only eight weeks mate as for a hygrometer we use em here all the time but the average tiler wont have one cos they are €600 here for a cheapo

tel

 

[Ajax123]

most screeds are modded these days i cant think of anyone i know who would wait 5 months for a screed to dry out i think bal even reccommend only eight weeks mate as for a hygrometer we use em here all the time but the average tiler wont have one cos they are €600 here for a cheapo

tel

Hi Terry

Where abouts in the world are you. 600 for a cheapo hygrometer is robbery. They're about £80 here although you could spend thousands if you wanted to. As for the screeds still probably 50 or 60% of the sand cement in the UK is site mixed sand cement. There are around 30 million square meters of screed laid in the uk each year and 70% of that is hand laid so 50% of that is still a lot of "traditional" sand cement screeed. People don't realise often how long it takes to dry properly (or don't want to co its cheap)and equally unfortunately are often given unreasonable expectations by suppliers. Anhydrite is a good alternative cos it can be laid much thinner so the drying time is less but you do need to know how to treat it properly to make tiling on it successful. Training is available. I agree there is a lot of mod screed about. I guess it just highlights the need to know what substrate you are laying on.