Edge tiling

[Nigel123]

On my rear sloping roof extension, I can slightly lift up all the edge tiles (about 15 of them) and the edge cement moves up and has a few small cracks. Do I have to knock out all the old cement & then re do it or can I run a small bead of mastic along it? Any thoughts appreciated.

 

[datarebal]

mastic will just delay the proper job...a band aid.
depending upon the tile type, they need stripping down and re bedding.

 

[^woody^]

Don't lift the tiles up then.

If the mortar is solid, leave it.

Almost all verges have cracked mortar. And likewise for unbonded tiles.

 

[Nigel123]

I am getting a few spots of black inside the room, up high on a painted wall, directly below where thes tiles are. I was wandering if I am getting water seepage coming in to the space above the ceailing & the black spots are damp caused by this - Thoughts?

 

[vinn]

Why not post pics of the inside black spots and the external verge?

 

[datarebal]

Of course you could let the wind rip them off?

 

[^woody^]

Of course you could let the wind rip them off?

Do you mean that mortar holds down verge tiles, and cracked mortar means that the tiles will be flying off quicker than the OP can say "no nails"?

 

[^woody^]

Thoughts

My thoughts are that the chances of rain getting through that narrow gap, moving under tiles and felt, and moving across a wall, and then moving down the wall past the ceiling and causing damp, are much much less than the chance of black mould being condensation related.

 

[datarebal]

black mould will be condensation .
water in a small gap will freeze and become a big gap...