Cement broken away from corner roof tiles

How much do you need?

To mend very small patches, I have used Fischer Express Cement Premium

- it comes in a tube, to be used with a standard sealant gun.

It's made with some kind of resin rather than water, so it sets quickly, and is rock hard in a short time. However it may be entirely unsuitable for what you want.

John

Something like:

Dispense some into a bucket add a little water at a time and mix to the consistency you need.

How can they have the cheek to write "ready to use" on the tub?

Spose you could argue that is about as ready to use as you are going to get a cement based product, if you want to choose its final shape :-)

As stiff as you can handle it. The stiffer the better.

Bill

We still talking mortar here? :-)

For a verge you probably want a little bit of moisture in there to get good suction onto the tiles, but yup a fairly stiff mix will be good. (those premixed buckets tend to have some lime and plasticizer in the mix already)

Yup. I'd say you want a mortar as flexible as possible and not too strong. The ordinary mix most roofers seem to use on ridge tiles soon falls out.

Probably one of those cases where a traditional lime mortar works better.

The Marley-modern gable-end tiles of my 1976 house were bedded in the same reddish mortar used for the external brickwork, and then before it had set they scraped it back a few mm and worked a layer of mortar with a black dye. This bedding is still present and is sound. When I did some work on the corners, I was amazed at how strong this mortar was. Very difficult to remove from the tiles and needed to be wacked really hard with a club hammer to break it up.

No you want it as strong as hell.

Bill

Roofs tend to move a bit. Being timber based. That's why ordinary mortar falls out.