wall cracks

davebap

New Member
good afternoon all,

im new on here, iv been plastering for about 4-5 years, (along with other trades iv learned in the same time, so dont plaster daily like most on here)and just done a job where i have scrimmed the cracks on the existing wall and overskimmed, but the cracks have reappeared within 2 weeks. i have never had that happen before, do you have any ideas what it could be?

many thanks for any advice you could give, and please no sarky comments from what iv read in some of the other questions people have asked, im only trying to learn and see what i can do next time so it doesnt happen again
 

LTJ

Active Member
good afternoon all,

im new on here, iv been plastering for about 4-5 years, (along with other trades iv learned in the same time, so dont plaster daily like most on here)and just done a job where i have scrimmed the cracks on the existing wall and overskimmed, but the cracks have reappeared within 2 weeks. i have never had that happen before, do you have any ideas what it could be?

many thanks for any advice you could give, and please no sarky comments from what iv read in some of the other questions people have asked, im only trying to learn and see what i can do next time so it doesnt happen again
Some cracks might’ve been small enough for you to miss when scrimming up
 
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paulf

Well-Known Member
Gone now, taped over
tenor.gif
 

Ktownsend

Well-Known Member
agreed pal.

some think that finish plaster is a miracle product but it cracks just like everything else no matter what you do, you can only try to minimize the risk.
I remember 1 job. Reskim a bungalow. All ceilings sound but cracked. Rescrewed every joists meshed the cracks with 100mm scrim and put fibres in 1st coat. All dried out and we were Fitting skirting boards and heard an almighty crack. Looked up and the ceiling cracked 1 end to the other. Couldnt believe the noise it made
 

bof

Well-Known Member
I remember 1 job. Reskim a bungalow. All ceilings sound but cracked. Rescrewed every joists meshed the cracks with 100mm scrim and put fibres in 1st coat. All dried out and we were Fitting skirting boards and heard an almighty crack. Looked up and the ceiling cracked 1 end to the other. Couldnt believe the noise it made
I've had it happen when I'd opened patio doors to do some floor sanding one cold winter's day
Put it down to rapid temperature drop contraction
 

davebap

New Member
the crack was on a reboarded wall, (about 3" from the end of the board) that had been channeled out for new rad pipes so i filled in behind the board to re secure then bonded over the pipes which was left off overnight as to not let the plaster dry too quick, even scrimmed where the bonding met the board and that cracked aswell,

also thanks for all the advice so far
 

bof

Well-Known Member
the crack was on a reboarded wall, (about 3" from the end of the board) that had been channeled out for new rad pipes so i filled in behind the board to re secure then bonded over the pipes which was left off overnight as to not let the plaster dry too quick, even scrimmed where the bonding met the board and that cracked aswell,

also thanks for all the advice so far
And you insulated the pipe of course
 

Wayners

Well-Known Member
Masonry? Plasterboard?
If masonry dig out crack and I sometimes find it's right through to cavity. Most times it's not so I pva right in and fill before taping.

Wall to ceiling cracks in masonry I dig out and if blocks have cracked all the way through I use bolt resin and run up. When set fill then tape over.

If really bad I hack plaster off. Sand and cement fill or resin. Metal lath over. Plaster over.

Fibre fuse its best tape to use followed by paper then orange mesh imo.

Masking tape either side but this is resin. Dries in 2 hours rock hard.
iGxudSb.jpg


Digging out

hZPT40E.jpg


Different mesh tapes
YHb1eox.jpg


Do like fibre fuse tape though and I use tungsten scraper to quickly scratch channel sometimes to sink tape level with the surface over cracks so no bump to feather out.

Don't use metal lath much though. Needs must sometimes but big job fitting that..
 

tapit

Well-Known Member
Masonry? Plasterboard?
If masonry dig out crack and I sometimes find it's right through to cavity. Most times it's not so I pva right in and fill before taping.

Wall to ceiling cracks in masonry I dig out and if blocks have cracked all the way through I use bolt resin and run up. When set fill then tape over.

If really bad I hack plaster off. Sand and cement fill or resin. Metal lath over. Plaster over.

Fibre fuse its best tape to use followed by paper then orange mesh imo.

Masking tape either side but this is resin. Dries in 2 hours rock hard.
iGxudSb.jpg


Digging out

hZPT40E.jpg


Different mesh tapes
YHb1eox.jpg


Do like fibre fuse tape though and I use tungsten scraper to quickly scratch channel sometimes to sink tape level with the surface over cracks so no bump to feather out.

Don't use metal lath much though. Needs must sometimes but big job fitting that..
You and your tape.
 

Wayners

Well-Known Member
@tapit

Yeah
Last month I boarded bedroom and had no fibre fuse so used orange mech. Following day I coved then called back when dry to fine fill joints and noticed 1m hairline crack in one spot. Why? Dose my head in. I scratched back with tungsten scraper and cut fiber fuse to fit (15mm wide) toupret and set in. Put fan on and dry in a hour. I mist coated and I said I had some, and said it brightened room just to hide my repair. Fussy customers would of been on phone but dodged that bullet. Why do some joins get that hair line crack? Dose my head in..
 
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