How to get mastik to stay put?

[Deleted User]

About 5-6 weeks ago, my partner re-did the mastik around the bath as it was peeling off and I could see holes for water to run down behind the bath.

I've now notice some of those holes are re-appearing, albeit small. The mastik just doesn't seem to keep to the line. Also notice the sink now is going the same way.

He made sure he dried it all first and followed the instructions on the tube.

Has anyone else got any thoughts please??

Thanks

Browntoa

did he fill the bath with water before mastic was applied ??

modern plastic baths flex, filling it with water first means its at it's maximum flex before you fill the gap, once the mastci is dry let the water out

bernlyn

i agree with Browntoa. also make sure that the surfaces are absolutely clean and i would use a decent brand mastic as i have found that the cheapest isnt always the best and costs more in the end.

Volcano

Normally the bath is half-filled with water before applying the stuff, I assume you are using silicon sealant, not decorator's mastic?

moneysavingplumber

It needs to be sanitary grade silicone, mould resistant and high modulus. If in any doubt go to your local plumbers merchants and ask for Dow Corning 785. It's flexible and will withstand quite a high degree of movement.

[Deleted User]

Thanks for all your replies. I think my Dad has some Dow Corning somewhere!! I will ask him. And Bf didn't fill it with water, I assume he doesn't know that trick. I will let him know and hopefully the next attempt will be much better.

Thanks again!