DIY Doctor UK DIY Forums

Hi there, I have roofers coming in November to rebed my valleys (2) and check my ridge tiles. My tiled roof is very dirty and mossy and I would like to have it pressure washed, but with is better to have done first

Hi wolfreton
Unless you are having issues with the valleys I suggest you leave well alone.
Personally I do not recommend pressure washing roofs, it can remove the finished tile surface making the tiles porous and susceptible to spalling. There is also the damage caused by roof access and removal of any mortar in joints.
Regards S

Thanks S, I had the valleys done a couple of years ago but a poor job, almost all the mortar is falling out, cracked and dislodged, I was hoping to have it done, and he done with it.

Hi wolfreton,
From your description I suspect the job carried out a couple of years ago was just a buttering up of the sides of the valley.
Unless the old mortar is cut back so a good thickness of fresh mortar can be applied you will be in the same situation 2/3 years down the line.
Regards S

Yes, I believe the buttering up to be right, and yes, without the whole lot coming out and rebedded it will happen again.
My original question which you advised against, was the cleaning of the tiles, maybe not with a high pressure cleaner but a soft cleaner.
I would really like to fix this once and for all and get on to other stuff.
Thanks
Jim