Roof ridge tile repair

[thomp1983]

A neighbour popped round to say he could see a ridge tile missing from the back of our house.

The tile was on top of my garage and is undamaged, I then climbed up onto the ridge line and at least half the tiles are loose, they are cemented in place.

I don't know much about roofs so how do I go about fixing this, obviously they need recementing but do I need to break up and remove all the old cement, even the parts that seem solidly attached to the roof or can i just apply new cement over the old solid stuff and bed the tile onto it?

Also what mix for cement should I be using?

Thanks
Chris

 

[vinn]

Why not post pics of the ridge?
Typically all the ridge tiles have to come off and the roof tiles to be cleaned up - this would depend on the type, the age and the condition of the roof tiles.
Lightly tapping with a hammer or sometimes a cut with an angle grinder will remove larger bits of stubborn mortar.
Then relay with a fresh sand and cement mix of 3:1.

 

[thomp1983]

Sorry for the delay,









The small extension in the last picture is where the ridges blew off but ive inspected the tiles on the main roof and some are loose there too

 

[^woody^]

Yes remove all the old stuff, but keep some to pack below the joints.

3:1 mix, but dont use building sand, use sharp sand.

If you find that a few need to be done use a mix of 70/30 sharp sand and building sand to aid workability. Polish the mortar smooth with the trowel when its starting to go off.

 

[vinn]

Use a roof ladder esp on the main roof.
The end tile with the plastic cap looks like it should be re-bedded as well as its neighbour.
That mortar should lightly chip away - you dont have to be too fussy.
Remember to clean the ridge tiles besides the field tiles.
Do all loose ridge tiles - if it has loose bedding then lift it and re-bed it. Ridge tiles can, of course, be dangerous if detached.
Sweep down the roof after finishing.

 

[thomp1983]

Having looked at it when I was there today the whole lot on both roofs will want doing, I'll have to do it in a couple of stages to allow one part to dry before putting any weight on it