To caulk or not to caulk..

Mark M

Mark M

Mark M

Soldato
Joined
6 Jan 2006
Posts
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Location
Newcastle upon Tyne
I’m decorating a new extension and wondering what I need to do around the windows and patio doors? I was going to caulk but read a number of posts that say that matt paint will crack in the caulk?

The patio doors has a small amount of cracking around the new plaster where it closes due to the weight/force of the doors I presume so I’ll need to do something there.

Thanks.
 
I'd try using some frog tape on the emulsion, once it's had a few days to dry out properly, but leaving a gap wide enough for a bead of mould resistant silicone sealant. The reason for using the masking tape is the silicone will blead slightly into the emulsion but the silicone shouldn't dry out as easily as normal caulk. Ideally get a proper cramer fugi tool set so you can smooth out the silicone by just constantly pulling the tool over the silicone from one end to the other and it will give a neat bead. If it does leave a slightly greasy looking mark on the emulsion edge then wait until the silicone has cured well after a week or so and then mask it up with the frog tape and put a lick of a emulsion down that edge.

You basically don't want your plaster / filler going right up to the windows or doors, fill the gap with enough silicone to be proud enough that you can wipe the excess away with the fugi tool. Alternatively you could finish the edges off with some uPVC quadrant strips that you cut and mitre.

I used some of this around our bathroom window as the builders had left too big a gap and silicone would just split away from the wall if it's too wide a bead.

https://www.wickes.co.uk/Wickes-PVC-Scotia-Moulding---18mm-x-18mm-x-2-4m/p/121286

Some of this grab adhesive as it works on non porous surfaces, which is not the case with most.

https://www.toolstation.com/multi-stick-grab-adhesive-solvent-free/p38941
 
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I've always torn my hair out with this, whenever I use caulk it cracks. When ever I use silicon it peels away I places. Probably something I'm doing wrong put it's not exactly hard to apply so no idea what that might be!
 
Relentless81 said:
I've always torn my hair out with this, whenever I use caulk it cracks. When ever I use silicon it peels away I places. Probably something I'm doing wrong put it's not exactly hard to apply so no idea what that might be!
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Cheap caulk is no good anywhere, least of all in a hot room like a conservatory. Elsewhere you can use a decent caulk like around internal door frames, tops of skirting boards, between wall and stair case but use Polycell Flexible Gap Polyfilla. Use sparingly and with a fugi tool to give nice crisp lines that you can paint up to having masked it up. The silicone shouldn't come unstuck if the surfaces are clean and the bead is not too big. Again use a fugi tool as it will scrape a lot of it off to give a neat bead of between 8 - 12mm depending on what edge of the fugi tool you use.
 
theone8181 said:
What about acrylic sealant, is that printable?
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Usually it is but it usually doesn't look good painted. You're better off using a sealant the same colour as the window or door frame. Acrylic can lack mould resistance too and be more porous than silicone.
 
I’ve just used a lot of CT1 on my extension it’s amazing stuff, used it everywhere. It seals, sticks and is paintable. It also comes in lots of colours.
 
Similar to CT1, I used some 'The Works Pro Sealant' in oak for our Velux windows. Looks much better than the white that the builders put around them.
 
Mark M said:
I’m decorating a new extension and wondering what I need to do around the windows and patio doors? I was going to caulk but read a number of posts that say that matt paint will crack in the caulk?

The patio doors has a small amount of cracking around the new plaster where it closes due to the weight/force of the doors I presume so I’ll need to do something there.

Thanks.
Click to expand...

I have always had problems with caulking and I really don't like it. The problem is that all the different makes give wildly different results. There is only one at the moment that I know works, and that is something called CT1. However, it can affect the colour of the paint if it is painted too soon.
Normally I just use filler powder mixed with PVA for non moving joints, say around skirting boards and so on. Around windows though or other moving joints then CT1. But I apply it after I have painted. Although it says you can paint over it I would not put a water based paint over it for a few months. One thing I have wanted to try is sealing it with a shellac based primer before it is over-painted. That should work.
 
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