Hi

I need to have cracks on the screed on a concrete roof opened up and grouted, maybe with some modern rubberoid material from a gun.

As to the opening up, was thinking of a concrete router. Can one rent these and get the cutter blades, preferably in Chiangmai?

Not so ideal but actually may end up better is this blade I found at $55 in the US which looks like it fits a 4inch angle grinder. Use wet or dry. It has a V section so although the bends may not be so neat the V would be great.

Pointers to where to find these here in Chiangmai (or even BKK)?

Any personal experiences of this work much appreciated....

Thanks v much

That blade will be fine for what you want to do and there are secondhand tool shops but even a new small angle grinder is cheap.

Is the roof leaking ??

As you probably know flat roofs with hot sun on the thin concrete screed gets very hot while the dense concrete slab underneath stays cooler.

Obviously when the hot screed expands more than the concrete underneath then the screed will crack.

That blade will be fine for what you want to do and there are secondhand tool shops but even a new small angle grinder is cheap.

Is the roof leaking ??

As you probably know flat roofs with hot sun on the thin concrete screed gets very hot while the dense concrete slab underneath stays cooler.

Obviously when the hot screed expands more than the concrete underneath then the screed will crack.

Yes I think it's simply going to be a regular maintenance thing to do the whole area now then do as needed each year or two. Replacing the whole screed may bring one full circle back to where one started.

That blade will be fine for what you want to do and there are secondhand tool shops but even a new small angle grinder is cheap.

Is the roof leaking ??

As you probably know flat roofs with hot sun on the thin concrete screed gets very hot while the dense concrete slab underneath stays cooler.

Obviously when the hot screed expands more than the concrete underneath then the screed will crack.

Yes I think it's simply going to be a regular maintenance thing to do the whole area now then do as needed each year or two. Replacing the whole screed may bring one full circle back to where one started.

Tiled it with good quaility light coloured or white floor tiles.

Had no problem with my tiled balcony for nearly ten years.!!