Rendering around windows

4 May 2012
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United Kingdom
I own a 1900 terrace house and the windows are upvc. They have been inset into where the previous window was and there are concrete sills. There is a layer of brick which goes around the window and this has been rendered or plastered upon then painted white (on the outside). The rest of the house is not rendered. Near the bottom corner and upwards for about 1 foot the render is blown out I have broken some of this away and you can see some wood (I presume where the old frame was) and a gap of about 5 mm, if I look further up it looks like there is a larger gap. I was wondering whether firstly when I break away all the blown render if I should fill the gaps with either mortar or expanding foam and then secondly what the best way to render back over with is. The job that has done before isn't particularly smooth so I think even I should be able to improve on it.

Lastly there are some minor cracks in the sills and render, I was going to open these out and then fill them with Touprelith F. Then put a smooth masonary paint on top, is this the best way to do it.

Furthermore, to seal around the UPVC and the window I will remove the current sealant and then use an exterior flexible UPVC sealant, is this also the best way to do it.

Sorry for the great number of questions, and I will upload some pictures shortly.

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1. Post pics of reveals and sill.

2. PVC window installers when replacing wood frames, typically cut the horns off and leave them embedded in the masonry ( along with wooden fixings). see my post of: may 10 2011, in the windows and doors forum - "replacement frames - a deadly practice. a rant."

3. the masonry filler you mention is fine. But why has the sill cracked?

4. Is there a steel lintel in position above the pvc frame?
Thank you for the response, I am just uploading more of the sills and above the window. I don't think the crack on the sill is particularly major as it does not appear very deep. Not sure whether there is a steel lintel above the window or just the brick work is enough. The windows were already installed when I moved in and I am not sure a particularly good job has been made. I essentially want to make it as good as I can without spending masses of money. I hope the pictures are ok, I didn't want to remove all the blown render until I know what I need to make good, especially with the weather the way it is at the moment.

Any help is appreciated.
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1. The frame is under the interior brickwork. The outer head has a soldier course supporting it - the soldiers have dropped slightly, but thats common.

2. The sill has a pressure crack from the weight of the right hand, thin column of returning brickwork between frames.

3. Peering thro the "hole", is the wood referred to above to be seen to the left side? Is it fungal damaged? The only way to see the full extent would be to strip the trim piece of PVC and perhaps knock off more render. Any remaining bits of the original wood frame might have be to removed by opening up from inside the room.

4. To re-render, knock off until you feel the remainder is sound, then scratch on a tight coat of 3-1 sand cement, float over it with another 3-1 coat.
To fill the hole(s), pack in a semi-dry mix of 3-1 and tamp it down. Allow a couple of hours for it to settle and scratch over.

5. There is a crack across the left hand reveal render.

note: Perhaps sort out the wastes' plumbing tangle at a later date. Is the Soil pipe actually plumb, and is it clipped(secured) at intervals?
Thanks so much for the informative responses, you are correct, the wood can be seen on the left although it does not appear fungal damaged.
Regards the plumbing tangle to be honest I really just want to make the house look good as I am looking to sell in the next 2-3 years to move to the coast.

Once again thanks so much for your help I now know what to go and buy.
One more thing if you don't mind, the upstairs windows are also upvc but they don't have the render, just one line of bricks, the mortar between the window and brick is coming away in places, would I use the same 3-1 mix for this?
I presume that you mean a fillet of S&C instead of caulking. Yes, the same mix will do. Although, if the fillet will come away easy perhaps remove the S&C, clean it up and caulk the join between frame and brickwork.
So silicone waterproof caulk would be better something that can bond upvc and brick?
Yes, given the appropriate, above conditions.

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