Sandstone bay window - how to repair?

costnowt

I am currently carrying out some maintenance on the bay window of my house. My house is approximately 100yrs old (Edwardian) and the bay window is constructed from sandstone.
It seems that during a previous maintenance session the parapets at the top of the bay window were repaired using mineral felt. The problem is that this felt seems brittle and there are cracks and holes in several places. I have included some pics to illustrate the problem. As you can see from the pic. the sandstone is also cracked and loose. Is there a way of fixing it in place?

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I have had a roofer out as I suspected the flat roof of the whole bay window needed replacing, however he informed me that the roof is fine :j and I think he said the cracks in the mineral felt can be repaired with silicone. Is this right? If so, what type of silicon and how do I apply it? Are there any alternatives. Ideally I would like a tidy repair that looks like the original sandstone, is this possible with silicone?

Thanks
David

ormus

i would use glass fibre tape and epoxy resin on that job. simple to paint over.
using felt and mastic will do it, but leave you with a finishing problem.

costnowt

Thanks for the reply! :T Beginning to think no one would answer! I've had a quick look for the products and found these:

http://www.wickes.co.uk/Patch-Repair-Mesh/invt/221808
http://www.screwfix.com/search.do;jsessionid=GXCK0FNHQBBNUCSTHZOCFFA?_dyncharset=UTF-8&fh_search=epoxy+resin&searchbutton.x=10&searchbutton.y=7&searchbutton=submit

Are these correct? Will these items fix the holes in the mineral felt and also fix the actual cracks in the sandstone? One of the quotes we had for flat roof included fixing the sandstone with metal rods?

ormus

the mesh is ok. not sure about that screwfix resin.
inserting steel rods (SS) maybe a good idea too.

costnowt

Any idea where I can get the epoxy resin from? Also the rods and how would I fix them?

Thanks

ormus

screwfix sell ss threaded rod. a pack of 12 inch rods is less than 5 quid.

its_all_gravy

You can get the resin from most builders merchants in the sandstone colour
I have repaired a bay using this stuff some years ago for a mate and it still looks good today
Do small manageable sections at a time and keep it tidy you shouldnt have any problems

stone7

The photos don't show any holes in the mineral felt. The arrows are pointing to areas of paint that have flaked off.

The felt issue. Cut the felt down by 50mm, nice, neat and level. Apply 100mm flashband around the top of the felt, 50mm on the felt and 50mm oversailing the felt. Apply the flashband using heat, either from a blow torch or, to save money, your wife's hair-dryer.

The stone problem. If the piece is loose, take it off. You will probably find a ferrous fixing that has rusted excessively and caused the cracking. Remove the rust by hammer & chisel, wire brush or grinder. Ensure the surfaces of the stone are dry and dust free before sticking the piece back on using polyester resin bought from Halfords (car body filler). Fill any voids or cracks with sand & cement and paint over in a few days.... job's a good 'un.

Don't try to insert rods into the loose section of stone... it's too fragile and will shatter.

costnowt

stone7 wrote: »

The photos don't show any holes in the mineral felt. The arrows are pointing to areas of paint that have flaked off.

The felt issue. Cut the felt down by 50mm, nice, neat and level. Apply 100mm flashband around the top of the felt, 50mm on the felt and 50mm oversailing the felt. Apply the flashband using heat, either from a blow torch or, to save money, your wife's hair-dryer.

The stone problem. If the piece is loose, take it off. You will probably find a ferrous fixing that has rusted excessively and caused the cracking. Remove the rust by hammer & chisel, wire brush or grinder. Ensure the surfaces of the stone are dry and dust free before sticking the piece back on using polyester resin bought from Halfords (car body filler). Fill any voids or cracks with sand & cement and paint over in a few days.... job's a good 'un.

Don't try to insert rods into the loose section of stone... it's too fragile and will shatter.

Aaah! I've just spent an age looking for epoxy resin at various known builders merchants, search engine - 'builders merchants+epoxy resin' and in the end asked the search engine where can I buy epoxy resin from. I learnt It can be purchased from automotive shops, boat chandlers and model making shops. By which time I come back to my thread and you've already answered it for me! :wall: I'll accept that the poster who suggested builders merchant had good intentions.

At least I'm a little more clued up on epoxy resin! Turns out there several different kinds. And I've realised it's what my neighbour uses to build all manner of things that I've looked and marvelled at. :j Oh, and my keyboard is playing up - have to type everything two or three times! :mad: I said earlier that I thought it was going to be one of those days!

Perhaps you can't see it in the photo but I'm pretty sure that what flaked off was not paint. When it come off the stuff is brown and about 1.5mm thick. It has been painted over with white paint. One of the roofers suggested mineral felt. Here's another photo.

costnowt

First of all thank you to all the posters. Job finished today - done by roofer. He removed the old flashing around the stone and brickwork, cut a chase and inserted lead. Finished off by sealing joint with silicone. The roof deck which was mineral felt was then painted with a fibre glass resin solution, he also painted this solution over the lead apron and up the inside of the battlements. He was going to fit 4 dowels into the loose battlements, but in the end only fitted one as the sandstone started to disintegrate during drilling (it was actually a mix of paint layers, torch on mineral felt, polyfilla and empty space - obviously a previous botched repair). I didn't mention it previously because I forgot but the crack across the top of the battlement actually continues vertically for about 15cm down the front, turns 90° and continues horizontally for about a metre along the front of the battlements before turning 90° again and continuing vertically up to the corner battlement on the other side. I can push it at the front and the whole lot moves! Don't know if the roofer is aware. It occurred to me that more dowels could be inserted along the length of the battlements to fix them in place and the crack can be filled and painted. What do you think? If this is not clear, I'll take another photo tomorrow.

costnowt

Sorry I didn't post the pics, having problems uploading them: Thanks