Painting crack in brick windowsill

[junebug29]

So. I want to repaint my windowsill but it has a huge crack in it. See picture. The windowsill is sturdy si I don't think it is structural but I do want to fill out in. What are my options?

Also I have other windowsills with much smaller "hairline" cracks that are perpendicular to the direction of the windowsill. I assume those are easier to fill with some kind of outdoor cement version of polyfilla. Is that correct?

 

[Doggit]

Sorry, but that window cill has had it, and needs to be rebuilt. If the crack goes outwards from the window, then it can be dug out, and an exterior filer added, which you could do with that one, but at some point you'll need to bite the bulet, and repair it properly.

If you're lucky, the bricks inside the cill are still okay, so you would hack off the damaged parts, build a wooden frame to encase it, and then fill with cement and sharp sand.

 

[junebug29]

Ah, so such cracks cannot be easily repaired? I was hoping I could fill out in with something. But what you are describing sounds over my pay grade so I will have to hire someone.

So, if I do get someone I should get a quote to replace the whole thing? How big of a job is that for a professional? It's off because it doesn't look like that big of a crack.

The other cracks are minor and look like in the attached picture.

Should I also move this to the building category? Maybe that is more appropriate.

 

[Hot&Cold]

If the cracked segments are loose and can be moved by light pulling action,then they are beyond repair.

Otherwise,clean them, wire brush the cracks remove any loose masonry,sand the cill,vacuum the cracks to get all the dust out then fill with 2 part filler (same stuff as car body filler) have a practice with the filler it sets rapidly,push the filler into the cracks and sand smooth if required.Then paint. https://www.toolstation.com/shop/p1...=16873&gclid=EAIaIQobChMI1u77sv-r1gIVG5SyCh20

 

[Doggit]

Having read Old&Bolds comments, if the bits are stable, then rather than 2 part filler, if you can thoroughly clean out any dust in the crack, the a 2 part resin would be a better idea, as that'll glue both parts together, and will be better long term than the filler. But you've got to sand it down before it sets solidly, otherwise it's a pig to work once it sets hard.

 

[Nige F]

Gripfill Xtra would be good - squeezed in with a mastic gun -suitable for outside use.

 

[junebug29]

Thanks all. I think my first picture didn't do the stability justice, so here is a second. In this first, the crack looks like it's a fairly substantial portion of the window, but it only goes half way as you can see in the second pic. As far as I can tell, the thing is rock solid. Pushing or pulling the thing won't make it budge.

 

[junebug29]

Gripfill xtra looks basically like a glue, and not really a filler. WIll that be good enough?

@Doggit: what "two part resin" did you have in mind? I'd prefer not to put in wood filler. Wood filler, I just found out the hard way in a painting project, sets very quickly. But I have no idea how strong it is.

While I am here, I used wood filler to fill depressions in exterior would (basically like filling in screw holes and old paint depressions to make the would appear flush after I scraped away layers of loose paint). Would pollyfilla have sufficed? is wood filler for more substantial structural holes?

 

[Burnerman]

Personally I'd glue that crack with a resin adhesive called Araldite.
Maybe the crack has been caused by a steel reinforcing bar rusting within the sill. Can you safely get there with some ladders....maybe to grind the crack flat first?
John

 

[Mr Chibs]

I've just redone all the cills on my house (6 x 1.1M), they weren't as bad as yours, but they were very scabby.

I used this:
https://www.toolstation.com/shop/p7...MIgdDPzv_F1gIVSYGyCh240gixEAQYASABEgKr5vD_BwE

I just used some thin metal scrappers to apply.

It's made a cracking job, it's easy to sand... it's a bit like plaster of paris.
Too dark to take a pic.

 

[Doggit]

If the cills are solid, then I reckon you could follow Mr Chibs suggestion, but if the cills are loose at all, then go for something like this, they're all pretty much the same, but you have to make sure there is no dust in the joint, or it won't hold, so you either need a dust gun to get rid of it, or wet the joint and let it dry first.. They can be pumped from a mastick gun, but they mix in the nozzle so it'll go hard and set, so you need to be ready to do all the filling in one go.

 

[Nige F]

Gripfill xtra looks basically like a glue, and not really a filler. WIll that be good enough?

I recently used it's interior version in a section of plaster cracked over the inside of a window head ( concrete lintol ) the crack was 2-3 mm wide and 150mm long - plaster was blown. The window was replaced a week later and all that happened was a short hairline crack @ the end of my repair - that's on a 6 foot long window. 1 tube in a mastic gun - job done

 

[junebug29]

The product that Mr. Chibs is talking about is exactly the one I bought to fill in my minor cracks (the one in my second post). I agree, that product is brilliant to work with (easy to mix, easy to sand etc etc) I bought it LSDM. The guy recommended a different product (possibly from the same brand) if I wanted something that will harden stronger for a more substantial crack. He said it works the same. By the way, Mr. Chibs, can you tell me the ratio of water to powder? LSDM sells little baggies of the stuff, but it doesn't have instructions on it.

I am intrigued by Nige F's experience with Gripfill xtra. that looks like it is might be easier to work with having a gun and all. Also, it sounds substantially harder than "just a glue" as I thought.

 

[junebug29]

it sounds like, however, both will be plenty strong. I would like a solution that makes the sill stronger.

 

[Doggit]

Then you want the 2 part resin; it's stronger than concrete in about 20 minutes, but you must make sure the surfaces are dust free, or it won't stick.