Ceiling cracks along steel beam after extension - Should I be worried?

[Dr_D]

Hello,

We had a 37 square metre extension built this summer. This involved knocking down the full width ground floor rear wall and installing a steel box frame to support the first floor and new extension flat roof.

The works were fully completed (decorated to finish) in September. Now we are getting a lot of cracks in the plastered ceiling. They run along the run of the steel beam and branch out along the ceiling, perhaps lining up with the floor joists.

Is this to be expected given the scope of the work we had done, or should I be worried that there are structural issues?

Any advice much appreciated.

D

 

[Notch7]

Hello,

We had a 37 square metre extension built this summer. This involved knocking down the full width ground floor rear wall and installing a steel box frame to support the first floor and new extension flat roof.

The works were fully completed (decorated to finish) in September. Now we are getting a lot of cracks in the plastered ceiling. They run along the run of the steel beam and branch out along the ceiling, perhaps lining up with the floor joists.

Is this to be expected given the scope of the work we had done, or should I be worried that there are structural issues?

Any advice much appreciated.

D

Most probably plaster shrinkage.

Timber used for ceiling joists etc is almost always stored outside at the merchant. Whilst the build is going on there are plenty of wet trades keeping the humidity high.
Then when the builders have gone you move in and the missus cranks up the heating
Wait until spring, then caulk and redecorate the ceiling

Only worry if you have cracks in the external brickwork above the steel or internally in the rooms directly above -say cracks at the corners of any windows, or in the corner of the rooms.

 

[Dr_D]

Thanks for the advice.

I thought I would add some photos, although it's hard to pick them up well on camera. Do these look like plaster shrinkage cracks to you? Seems strange that they track along the line of the steel.

Also, the day the plasterer skimmed the ceiling it was very hot, about 35+ degrees. I've heard plaster can have problems if it dries too quickly, could this have contributed?

 

[Dr_D]

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