Paging 'Roughcaster'

[Shutpa]

Noseall tells me that you may be able to help me.
A 6" piece of off-white concrete or cement has fallen from the window surround and the builder who promised a repair never appeared. The scored cement under the outer layer is still intact and I would like advice on how to tackle the repair myself. Can you help please?

 

[roughcaster]

First of all Bolo, you can't patch harling without it being noticeable, but the smaller the patch the less chance of seeing it. First of all, have a gentle tap, with say a small screwdriver handle around the damaged bit (front wall) and above and below on the window reveal. You're listening for a hollow sound. If it sounds solid all round, and above and below, no problem. Tap the scratch coated area as well. Do that for now,, and let me know what's happening. I've more to add tonight,when I have your update, and we know which way things are going.

Roughcaster.

 

[Shutpa]

Have tapped both the underlayer and the surface one and neither have the hollow sound. Re the difficulty in matching harling there is only about 35mm of the actual front wall missing. the remainder of the L-shaped piece formed the part of the window surround and wasn't harled.
Hope this helps to define the problem.

 

[roughcaster]

Ok Bolo, this might sound daft, but I would do this patch in two parts. The window reveal repair first, let it set a day or so,and then the small front patch,,,, that way you are working from a hard edge... If you do it in one go, you wont get the sharp look on the window reveal corner..... You'll need a "small" amount of Snowcrete white cement, some plastering sand, "small" amount of lime and a waterproofer/ plasticiser. Hopefully you can get these from a friend for all you would need. As regards to the chips, just go along the wall of your house, and "gently" rub a piece of wood or something similar onto the wall, "here and there", and catch a few of the original chips onto a piece of polythene/paper, just enough to put onto the front of the patch, that way, they are identical, and you wont need a lot anyway.... More on the way.

Roughcaster.

 

[roughcaster]

Mix up your Plastering sand, Snowcrete and lime to a 5-1-1 ratio adding the waterproofer/plasticiser to the water in the bucket. Mix up the mortar to a buttery texture, not too much water, but give it plenty of turning over when you mix,,, puts air into it and makes it light .... Give the window reveal patch a wet brush and pva, then hold, or stick, (with mortar,,,don't nail), a small piece of wood on the face of the wall to give you a neat square edge, and then with a trowel, apply some of the snowcrete mix to the window reveal, bringing it out flush with the original, leave it for a while to steady up, and then holding the small straight edge tightly, rub the mortar with a float to give it a uniform finish, keep it flush and neat where it joins the original,, leave it again for a while and then run a sponge over it, when you're happy with it, leave it to set,,,,, with the straight edge still in place....Hope you're following all this, it's hard to put into words...... A day or two after, mix up another even smaller amount of the mortar, same mix, damp down/pva the front of the wall, apply the mortar to the wall, out to the original thickness, making sure you cut it in very neatly against the original harling, and also let it very slightly overlap the window reveal edge, and while the mortar is still "wet", gently throw your chips into it, making sure you catch 'em all, and any areas that need more, then put them in with your fingers, if you throw too late, you can knock off what you've just put on,,, don't fiddle with it once it's on either..... To be honest I hope your builder comes back, or you have a mate that can help you out. The builder would do it no time. It's probably taken me longer to try to explain than it would take to do. If you lived around the corner Bolo, i'd do it for you....... I hope that helps enough for you to do the repair, but if not, at least it gives you a rough idea... A little tip,,,,, put a layer of clean sand onto the window cill, to keep it from getting covered in cement..

Roughcaster.

 

[Shutpa]

Thank you Roughcaster for taking the time to key that lot in! And yes, your instructions are crystal clear. The only question I have is regards the lime. Are we talking about a dry powder, a soft mortar type paste, or a liquid?

Might give it a week or two to see if the builder does turn up but I wont bank on it. Anyway, thanks again for the advice - I will try to follow it to the letter.

 

[roughcaster]

That'll be a bag of "powdered" hydrated lime, you can get it from any builders merchants.... But if you can, get a builder friend to give you: One shovelful of Plastering Sand, One shovel of Snowcrete (white cement), and a shovel of powdered hydrated lime,and a small amount of waterproofer/plasticiser,, then using a small container, eg. (empty yoghurt pot) you can measure out your 5-1-1 each time, and mix a small quantity in a bucket. Mix it dry first and then slowly add the water, mixing it well. The added waterproofer/plasticiser means you wont need much water.I hope you can get the bits and pieces you require, it'll save you buying a bag of this and a bag of that,,,, for all you'll need..... Why not ask Noseall nicely...

Ps. Measure and add the W'proofer/plasticiser to a bucket of clean water (again,use a small yoghurt pot as a measure,) and stir in well, then add the required amount of water to the mix,from that bucket.

Roughcaster.

 

[Shutpa]

Why not ask Noseall nicely...

I cant ask Noseall because I dont know who he is, or where he lives. He is simply, like you and I, a contributor to DIYnot, who noticed that I had posted my harling problem in 'Building' instead of here. Thanks again for the added info.

 

[roughcaster]

Why not ask Noseall nicely...

I was just kidding there Bolo. Good luck anyway.

Roughcaster.

 

[Shutpa]

Noseall tells me that you may be able to help me.
A 6" piece of off-white concrete or cement has fallen from the window surround and the builder who promised a repair never appeared. The scored cement under the outer layer is still intact and I would like advice on how to tackle the repair myself. Can you help please?

Mrs B called me to the bedroom today (?) and asked when the builder had repaired the damaged harling. My answer was, that I had no idea, but it has been repaired, I know not when. Thanks Roughcaster for your contribution.

 

[roughcaster]

Glad to have helped out Bolo. Was it you who did the repair in the end, or did the builder really come back and do it for you? Either way it's done and that's the main thing..

Roughcaster.

 

[Shutpa]

Was it you who did the repair in the end, or did the builder really come back and do it for you?

The builder did!