Best way to repair tiled gable roof end?

[dogfonos]

Would appreciate advice/guidance on the following matter...

I'll do my best to use the correct terminology to describe the situation but please be aware I may not get it right!

I had a few minor roof works carried out 8 months ago by a reputable local roofing company. One job was to re-bed the final row (drip edge?) of concrete roof tiles, that had slipped down and twisted out of position at a small gable end/verge. They did a tidy job, bedding the tiles down on concrete on top of a sheet of thin material (don't know what this is, wasn't there before) lying against the rake.

Trouble is, I've just noticed that the concrete has cracked in a couple of places and at one crack, a group of tiles (at one lower end of the gable - all concreted together) has slipped down and twisted out of alignment - just like before - leaving a gap about an inch wide in the underlying concrete.

Up to 8 months ago, the gable end/verge tiles were bedded onto concrete on top of a row of tiles, rather than thin sheet material, and they rested against the rake (which is horizontal siding).

I will call the roofers back but before I do, I'd like to be a bit more knowledgeable. What is the best way to repair or rectify the situation? Should I consider gable verge tiles?

It only took a few months to badly crack up so I'm concerned about further cracks appearing at different points in the near future. If the roofers agree, I'd consider removing all the edge tiles and starting again using a different method but I need to have confidence in that method.

 

[terrypin]

The verge tiles are fixed using a dry system or cement/mortar bedded on to a fibre cement board(1:3 mix). Repointing is not the best solution where the mortar/tiles have come loose.

Remove verge tiles and re-bed.

 

[dogfonos]

Thanks for the reply, terrypin, an apologies if I've been unclear but the roofers did remove then re-bed the tiles - in fact they removed two or three columns/rows back and seemed quite thorough, I thought at the time.

What concerns me is that the weight of the tiles (plus attached mortar) is pulling the mortar apart and allowing a section of concrete tiles and mortar to slide down. Even if they re-bed the tiles (as they originally did), what's to stop the same thing happening again?

Concrete/mortar is very weak when 'pulled'. Surely there needs to be something else that holds/fixes the tiles in place to prevent them sliding? The concrete tiles have little protruding 'lugs' on the underside which normally fit over wooden battens to prevent downward movement but at the verge, I suspect these lugs just sit on the thin fibre cement board thus the tiles are no longer being held in place and so they rely on the mortar to do that. I'm no expert but that doesn't sound right to me. I would hope there's a better solution.

 

[terrypin]

The fibre board should be held in place by the batons and the tiles secured to the batons(nailed or eaves clips) and mortar bedded.

 

[dogfonos]

Ah. I don't know if the fibre board is nailed to the batons but these concrete tiles don't have nail holes. Nor did they originally have any type of eaves clips and I don't think any were fitted during repairs by the roofers. The only thing that could be holding the tiles in place is the mortar and, possibly, small lugs moulded onto the underside of each tile that 'hook' over the batons (but not, I suspect, where the underlying fibre board has been employed and I think that's the problem).

I'll get the ladder out tomorrow and snap a few pics to send to the roofing company then discuss a fix with them. Thanks for your help.

 

[catlad]

Hi Terry not seen you posting for a while did they let you out for good behaviour

 

[terrypin]

Hi Terry not seen you posting for a while did they let you out for good behaviour

Haha, you could say that, we(the lunatics)took over the asylum