Crack in exterior plaster

chuck eastwood

Hi guys. I am having my house painted next week and have noticed a crack in the plaster on the wall. What should or could I use to seal it. Should I grind it out and patch it with sand and cement or is there a sealant I can use. Hoping to do this tomorrow so any help would be great

mad m

Can you get any pictures of the crack and upload them.

chuck eastwood

just in the door, a little bit dark when i took the pic's but you could call it a hair line crack. palster seems sound either side of the crack. Both pictures are about 2 foot square. the crack goes up about 8 foot then over about 8 foot

mad m

They look like very fine hairline cracks alright. You can get an exterior polyfiller if you wanted. Root out crack as best you can (with a flat head screwdriver) and spray some polybond into crack ( Get a waterbottle and mix some polybond and water in bottle and spray into crack). Then fill crack.

If you try and put some cement in that type of crack, firstly you will find most will fall to ground and it won't stay in crack. If you are really worried about it, then it will have to knock out about two inches of a hole the whole length of crack is so the sand&cement will take.

I've seen worse cracks to be honest, are these cracks showing on interior of your building? These just look like settlement cracks that happen normally in a building.

Oh just a tip, if you do fill with polyfiller. Fill it proud, leave till you think it might be nearly drying and smooth off with a wet sponge. Do it in a swirling motion. It will save you sanding it down and it will blend in with rest of render. You can do this as well with the sand&cement.

antiskeptic

chuck eastwood wrote: »

just in the door, a little bit dark when i took the pic's but you could call it a hair line crack. palster seems sound either side of the crack. Both pictures are about 2 foot square. the crack goes up about 8 foot then over about 8 foot

That second picture (309) seems to show a vertical joint between two walls: perhaps the main house and an extension, or the house and a garden wall. If so, then there won't be much point in filling it -the crack is occuring because the two walls aren't tied in together and the filling will crack again probably.

You could try though, in which case I'd vee out the crack - perhaps a 1/2" wide at the surface and going all the way to the block work - then fill it with sand/cement (with a little plasticiser/washing up liquid to make the mix more workable)

chuck eastwood

Thanks lad's. Yeah the second crack is the old coal shed joined onto the back of the house. not to worried about that but I'll fill it all the same. I had pulled down the plater board on the inside to re insulate. I saw a damp patch after a few days of heavy rain so I better do something with it now to avoid problems with damp later

antiskeptic

chuck eastwood wrote: »

Thanks lad's. Yeah the second crack is the old coal shed joined onto the back of the house. not to worried about that but I'll fill it all the same. I had pulled down the plater board on the inside to re insulate. I saw a damp patch after a few days of heavy rain so I better do something with it now to avoid problems with damp later

I'm just wondering would the famed Tech-7 be worth considering in this case. I'd use an angle grinder with suitable disc to cut a channel down the join - say 10mm wide, straight sided rather than vee shape - all the way down to the brickwork. Pay attention to 'working the Tech-7 into the join so that it adheres to the walls of the channel you've cut, smooth/press into the joint with a saliva wetted finger, then paint over. It would have a better chance of holding up than a sand/cement fill.

chuck eastwood

I used my chain saw to cut out about an Inch wide gap and I'm now in A and E....just kiddin. I used my grinder took about 8 mill out and used exterior filler which I later found out is very fine sand with a lot of cement in it both of which I already have.Eight quid for a bag of the stuff but did the job all the same.