Adhesive Expiry Date Advice

[Deleted member 57709]

Hi everyone, hope you are all well.

Two questions:

I want to tile over electric underfloor heating cables / Ditra Heat with 600x600mm large format tiles (9.5mm depth tile). My question is the adhesive that I have got which is the correct one for underfloor heating is 8 months old but on the manufacturers site it says ok to use up to 12 months old from date on bag but I'm a bit scared of using just in case it won't set properly. The adhesive has been stored in the house so at right temperature etc. Do you think I would be ok to use this as I have 15 x bags and really don't want to throw them out but at the same time don't want the job not right. Reason for age is because my mum and dad passed away recently so everything came to a stand still but now I want to get back to work and finish the job off.

Also I did some tests a few months ago to see what coverage I was getting and found I could get 90% coverage if I used a 20mm U notched trowel on floor and on back of tile which I know is a lot of adhesive but anything less did not give me the coverage required. I also use a 12mm square notched with 6mm on back of tile but it only gave me about 75% coverage. So would the 20mm U notch on both back of trowel and floor be ok. The adhesive can go to 22mm depth.

Many thanks in advance.

Gary.

 

[Dave]

Hi everyone, hope you are all well.

Two questions:

I want to tile over electric underfloor heating cables / Ditra Heat with 600x600mm large format tiles (9.5mm depth tile). My question is the adhesive that I have got which is the correct one for underfloor heating is 8 months old but on the manufacturers site it says ok to use up to 12 months old from date on bag but I'm a bit scared of using just in case it won't set properly. The adhesive has been stored in the house so at right temperature etc. Do you think I would be ok to use this as I have 15 x bags and really don't want to throw them out but at the same time don't want the job not right. Reason for age is because my mum and dad passed away recently so everything came to a stand still but now I want to get back to work and finish the job off.

Also I did some tests a few months ago to see what coverage I was getting and found I could get 90% coverage if I used a 20mm U notched trowel on floor and on back of tile which I know is a lot of adhesive but anything less did not give me the coverage required. I also use a 12mm square notched with 6mm on back of tile but it only gave me about 75% coverage. So would the 20mm U notch on both back of trowel and floor be ok. The adhesive can go to 22mm depth.

Many thanks in advance.

Gary.

The age of adhesive is fine. As for the coverage, how wet are you doing the mix ?

 

[Deleted member 57709]

The age of adhesive is fine. As for the coverage, how wet are you doing the mix ?

As per the bag instructions

 

[Dave]

As per the bag instructions

Ok. Are you serrating the adhesive in one direction, that helps with getting a solid bed. Imo 12mm trowel is fine and backskim the tiles.

 

[Deleted member 57709]

Ok. Are you serrating the adhesive in one direction, that helps with getting a solid bed. Imo 12mm trowel is fine and backskim the tiles.

Hi Dave, yes adhesive in one direction and same on back of tile and put down in same direction but found that the 12mm notch with 6mm notch on back of tile was only about 75% coverage where as the 20mm U notched trowel on both floor and back of tile gave me about 90-95% coverage but is this method ok to proceed with or would you advise a different way so coverage is 90%+?
Many thanks,
Gary

 

[Dave]

Hi Dave, yes adhesive in one direction and same on back of tile and put down in same direction but found that the 12mm notch with 6mm notch on back of tile was only about 75% coverage where as the 20mm U notched trowel on both floor and back of tile gave me about 90-95% coverage but is this method ok to proceed with or would you advise a different way so coverage is 90%+?
Many thanks,
Gary

Which ever way suits you tbh. Try sliding the tiles back and forth on the adhesive bed more to achieve better contact

 

[Deleted member 57709]

Which ever way suits you tbh. Try sliding the tiles back and forth on the adhesive bed more to achieve better contact

Ok I will do that, cheers and thanks for your advise, really appreciated.