Manhole benching repair

[normthenorm]

Hopefully correct forum. Looking to patch repair the benching in our inpsection chamber where the toilet waste goes. it is starting to fail where it meets the clay pipe, leaving a hole. Has anyone used this stuff: Everbuild Jetcem Waterproof Rapid Repair Cement? If so would you suggest using SBR first? My plan was to stuff the hole with a semidry mix of the rapid set and finish as best I can just around the hole - and once that has been left to set fully I thought about going over the entire benching with some sort of epoxy skim. Or does that sound overkill?

 

[Ivor Windybottom]

Jetcem - Yes, ensure nothing in use, plug the exit hole to ensure nothing goes downstream. Clean tools quickly after.
SBR - Yes, good idea
Epoxy skim - don't bother, not necessary, more likely to peel off and cause problems itself

Rothenberger 130091 | 4" Steel Drain Test Plug 100mm

Rothenberger 4 inch Steel Drain Test Plug Steal drain test plug used for sealing off drain pipes prior to testing. Key Features and Benefits: Drain Test Plug Manufactured in Steel C/W Protective Plastic Thread Cap 4″ Diameter 1 Year Manufacturer’s Warranty 130091

www.stuartplumbing.co.uk

 

[Ivor Windybottom]

+ Give everything a blast with a hosepipe first to remove slime

and remove any loose chunks completely. Better to fill a bigger hole than to try and glue in a loose chunk.

 

[normthenorm]

Excellent - thanks for the speedy reply. So a patch around the immediate vicinity finished off neatly should be fine? Yes - I was going to hose down and give it a brush down with a stiff brush and plug.
We do tend to check our drains on a weekly basis anyway for blockages as we are on a private system which when installed wasn't the best work - so the odd bit of snagging doesn't worry me too much. Its the possibility of chunks of benching floating down that is the immediate concern.

 

[^woody^]

Is it your manhole or the water company's?

 

[normthenorm]

Is it your manhole or the water company's?

Ours. On a private tank

 

[^woody^]

Just use a strong 2:1 mix of sharp or screed sand. Sbr is optional, fine of you have some, but not worth buying if you don't or won't use it elsewhere. Prime with cement slurry.

Can you place a board or polythene over the repair for protection until it it goes off? Your looking at 48 hours.

Otherwise use an epoxy repair product.