Pointing repairs on roof - cement or mortar?

Ant555

There are a couple of places on the side gable edges on a pitched roof over an extension that need repairing.

Do I need cement or mortar?

Screwfix have options labelled as...
5Kg of mortar
https://www.screwfix.com/p/cementone-general-purpose-mortar-5kg/36857
or 10kg of cement
https://www.screwfix.com/p/no-nonsense-rapid-set-cement-10kg/3794h

Thanks

EssexExile

They are both mortar.

Tom99

Given the job you are doing I would not get the rapid set stuff. The general purpose stuff should be ok. I normally put a small bit of washing up liquid into the mix it makes the mortar more pliable with less water.

Mr.Generous

I'd use a waterproofer admix which also acts as a plasticiser, always worth it on a roofing job. If its ridge tiles take them off and bed them into the mix, don't just try and point them in.

Ant555

Thanks for the replies.

I didnt really know what the names of all the parts were but after a bit more googling, I believe I am talking about verge pointing but it looks like all the information is valid.



https://www.diynot.com/diy/media/untitled.9756/

neilmcl

Just get a bag of cement, bag of builder's sand and mix your own - https://www.youtube.com/watch?v=X0q_2VuFUOI

lg13mza

if you want it to last I would want some sharp sand in as well. Harder to work with, but will last better. I can't remember the exact mix but I searched it on diynot.

James_Green_1982

neilmcl wrote: »

Just get a bag of cement, bag of builder's sand and mix your own - https://www.youtube.com/watch?v=X0q_2VuFUOI

Is that much cheaper than ready-mixed cement?

stuart45

lg13mza wrote: »

I can't remember the exact mix but I searched it on diynot.

50/50 sharp/building sand is commonly used in the trade.

garrysibbald

Tom99 wrote: »

Given the job you are doing I would not get the rapid set stuff. The general purpose stuff should be ok. I normally put a small bit of washing up liquid into the mix it makes the mortar more pliable with less water.

Washing up Liguid? Using washing up liquid instead of a recognised plasticiser is a sackable offence in our company.
:rotfl:

Tom99

garrysibbald wrote: »

Washing up Liguid? Using washing up liquid instead of a recognised plasticiser is a sackable offence in our company.
:rotfl:

It is Fairy, not the cheap stuff!