Mortar bed under concrete tiles

[CANDYPANDY]

Hi ,
can anyone give some advice on the following.
Since having upvc soffits ,bargeboards and guttering installed about 10 years ago I have had problems with the mortar beds under the first 2 tiles at each of the 4 corners of my roof. These mortar beds were disturbed at the time of installation of the upvc rooftrim and hence renewed. Around 5 years ago one lump of mortar from under one of the corner tiles started to slide outwards and threatened to fall from the roof. I removed the lump of mortar myself and packed under the tile a really good dollop of mortar -perhaps 2or 3 times the amount normally used, I don't know because this is the only roofing work I have ever done-ie
complete novice. Recently the same is occurring on another corner of my roof- ie lump of mortar sliding outwards . This time decided to get a roofing contractor in to sort this one out. The man who came to look at the job said that the first two tiles at each of the 4 corners needed lifting and rebedding onto sand and cement. Here' my dilemma -continued

 

[Alastairreid]

not an uncommon problem! the contractors who fitted the new facings/soffits should have rebedded them.

 

[CANDYPANDY]

the roofers turned up today and made a start. At the corner that I had previously renewed about 5 years ago -incidentally this still looked perfect just like the day I put it there however the mortar bed under the next tile above looked cracked and a bit dodgy -I did not replace this at the same time because there was no sign of it moving and I was not comfortable going any further up the ladder. Hence the roofer could not lift this first tile because I guess I had done the job that well and the tile was really well bedded onto it. Heres were the worry lies- guess what for some reason the roofer has hammered the mortar bed further under this tile ,intending to skim over with fresh mortar so he says -back on Monday to do this weather permitting. This seems a bit of a cowboy job to me and not what was supposed to happen according to the estimate. Can any one advise on this especially on any possible damage that may have been caused by the hammering or am I worrying unduly.
Thanks for any guidance

 

[Alastairreid]

i think you may be worrying over nothing.

when the roof was originaly tiled the verge tiles would have been laid on a bed of mortar then pointed up.

its quite acceptable practise to remove the dried out mortar verge and block out with fresh mortar then point it up once the new bed has taken up.

dont accept him putting a skim of mortar over the existing verge as it will fall back off sooner rather than later.

and if he has quoted to rebed and point the verges make sure thats what he does.