Window sill

[expat paul]

Hi,

I have a concrete window sill that needs some tlc, the leading edge (corner) has large pieces missing and the slope is very minimal, otherwise its in good nick ie no large cracks. Anybody know what the best way/product to repair it?
I am thinking of roughing up the surface with an angle grinder, a coat of PVA, a piece of shuttering against the front face and float on a stiff mix of sand cement. Will this do the trick ? and if so, what is the minimum thickness of sand cement so it doesn't crack? the window is south facing so gets very hot and cold.

thanks

[Pierre ZFP]

Hmmm, not easy.  There is some stuff you can get for repairing the edge of steps etc which may work, I feel that just concrete will quickly crack again.  Have you considered tiling the sill with complimentary/contrasting tiles or stone?

[expat paul]

Yes, cracking is my worry, I'll look for the stair repair stuff tomorrow. If I can't find it, I like the tiling idea, thanks 

[expat paul]

 I went for the Silkatop 122F concrete repair as it looked like someone had already tried the sand/cement method and it had been that which had broken off. It seems at the moment to be very good stuff.

Another question on the same subject if I may, I have some small cracks and small chips in other concrete sills I would like to fill before masonary painting, any recommendations on how to fill these, again with regards to the extremes in temperatures.

thanks

[Pierre ZFP]

If you're going to paint over cracks and chips then there is much less of a problem.  Small bits of filler, specifically exterior filler, will expand and contract in much the same way as concrete, ie not much. Painting will prevent the ingress of water which is the main problem as when it freezes - bingo - another crack.  You should be OK though

[expat paul]

Ok thanks, I was thinking of exterior filler but thought that was way too easy   [:$]