Need good sealant for guttering

[Hajj]

Hello. A workman has replaced a portion of my leaky guttering but it still leaks. He came and put some sealant but it must have got shrivelled up in the strong sun because it is leaking again now.

Any recommendations for a good external sealant for plastic guttering which will not crack?

Thanks,

Hajji

 

[vards01]

Dow Corning 791 would do the trick, available in black or white, round about £5 a tube.

I would get the workman back to sort it out, pretty poor job if he replaced leaky with leaky......

 

[Blagard]

A sealant on plastic guttering ?

If plastic guttering is leaking there is usually a fault that needs attention.
Maybe a union clip is broke, or a rubber seal needs resetting/replacing. Sometimes too much room for expansion allowed causing the gutter to slide off a seal.

All can usually be remedied properly. Sealants won't stay stuck to the plastic because plastic moves (expands & contracts) and if gunned into dirty joints won't last anyway.

A neighbour of mine asked if I would look at his because it still leaked after he had tried to "fix it" It was a bit of a laugh, after I unpeeled the mastic used, unwrapped the duct tape and removed the upside down fitted seal. Cleaned the union, re-fitted the seal right way round, used a bit of silicone grease in reassembly and reset the gutter that had crept in one direction until off the seal. Now it looks like new again and doesn't leak, If it creeps off in one direction again, fitting an extra union will take up the excessive expansion allowance made by the original installer.

 

[joe-90]

Silicone grease is a good idea. I've got some but never thought of using it in that way.