Roof cement
 

What is the white coloured mortar that roofers use for ridge tiles etc. Also has anyone tried mixing fine hardcore with cement, does it give a strong finish.

Re: Roof cement
 

When I secured some ridge tiles I used flexible tile adhesive. Not strictly for the job but it's sticky and frost resistant.

Re: Roof cement
 

6 parts sand, 1 part lime putty 1 part cement for the mortar although these days ridge tiles are usually fixed with screws with clips provided if they are new tiles or drilled through the apex (not with a hammer drill !) if old tiles.

Mixing hardcore with cement, I presume to make concrete, will work providing there are enough fines in the hardcore and the lumps are not too big. If it looks like all in ballast with a few bigger bits it should be OK. The target should be for the hardcore to consolidate down with no air gaps and there should be enough cement to evenly coat all the particles (fines, gravel sized bits and any lumps). Minimum water consistent with a good mix tamped down properly will give a stronger end result that a sloppy mix that is easy to pour. And don't let the concrete dry out too quickly. i.e. water it 2 -3 times a day for 2 or 3 days or wet it down and cover with a plastic sheet.
Oh and make sure you have a cat. I have yet to lay any concrete that did not finish up with cat prints across it !!

Re: Roof cement
 

Thanks all.