adhesive for underfloor heating

[tim000]

hi,

I am in the middle of tiling my bathroom floor. i am using NMP boards, then UFH followed ultra SLC. Which adhesive would you guys recommend to stick the NMP and tiles down with. i am going to screw the NMP, but my floor boards are a little bit bowed so would like to glue them down as well just for added peace of mind. Is there an adhesive i can use to do both jobs? I know i need a flexible adhesive suitable for UFH but there are so many different manufactures and such a wide range in price that i am a little unsure as to what would be the best for my installation.

 

[White Room]

Did'nt you buy the ultra sticky foam for the nmp...

 

[tim000]

No, the shop I got the NMP don't sell it. The guy in the shop was adamant it just needs screws. The boards arnt quite level so the addy would fill the gaps.

 

[Dave]

If you use anything other than the nmp megga glue , then you void the warranty... But as you say with bowed floorboards , I'm not convinced the megga glue will fill them like adhesive will .

so it would be Hardibacker for me , then a min S1 adhesive .

 

[tim000]

i have already cut the boards to fit, can you recommend an adhesive that would work well?

 

[Rookery]

Hardie for me too. Boards and tiles fixed with Keraquick.

 

[tim000]

Hardie for me too. Boards and tiles fixed with Keraquick.

Would you use latex plus?

 

[White Room]

i have already cut the boards to fit, can you recommend an adhesive that would work well?

A single part flexible S1 but use the nmp screws which have drill type action on them because it's quite a dense board.

 

[Lee@emctiles]

No, the shop I got the NMP don't sell it. The guy in the shop was adamant it just needs screws.

#gulp

really? you were advised by someone selling NMP that you didnt need the mega adhesive? I give in sometimes.

if you havent already laid boards, use the mega adh.

rest of the planned adhesive/leveller is fine IMHO

 

[Dave]

i have already cut the boards to fit, can you recommend an adhesive that would work well?

you can use tile adhesive but like I mentioned above you lose NMP warranty . Not the end of the world i suppose... The rep told me it is ok to,use tile adhesive just like hardi ... But prefer you to,use the megga adhesive and if the floor is cupping etc then use a few more runs of megga grip.

 

[SJPurdy]

With the Hardie boards the adhesive layer is only a gap filler, it is the approx. 35 screws per board that hold the board solidly down to the floor (and filler).

With the NMP it is the foaming mega glue that holds the boards down. The 8 screws per board hold the board down in place while the glue expands and then sets. If there is some slight cupping in the floor boards then I would use a few extra runs of the mega glue so that all areas are supported/glued. If there is more than a slight cupping then I would use another type of boarding.

 

[Stef]

With the Hardie boards the adhesive layer is only a gap filler, it is the approx. 35 screws per board that hold the board solidly down to the floor (and filler).

I know they say the adhesive is only a gap filler but have you ever tried to rip up Hardie after it's been stuck down?
I spoke about this a while back & the adhesive is more than a gap filler, I found this out myself when I had to replace tiles as the outlaws changed their minds about where the tiling was stopping.
I only took up a small section (900x300 roughly) & it took me ages.
You could in theory take all screws out of the Hardie after adhesive has set & it wouldn't budge.

 

[Rookery]

Would you use latex plus?

No