Hairline cracks after RSJ, should I worry?

[Nojjy]

Hi we had a load bearing wall knocked down 3 weeks ago between main house and extension, naturally an RSJ was put in place, we got it designed by engineer and building regs were happy with it.

However after it was done the bathroom door on the floor above is a little stiffer, and there is a crack above the door frame, additionally there is a crack in the corner of the extension bedroom.

Do they look bad, is this normal?



Many thanks

 

[^woody^]

Perfectly normal for a crap job

 

[Nojjy]

Sucks, so could it get worse?

 

[cjard]

Cut up an old credit card into long, slim triangles and wedge a few in the cracks. Leave it a few weeks. If they fall out, it's a pointer that it's getting worse. If they don't, buy some easifill and patch em up, sand and repaint

 

[Nojjy]

Luckily the cracks are too thin to stick anything in there at the moment, but I guess thats a good test, If I can put something in there in 2 weeks time then I know its got worse.

What would cause it to worsen? Foundation issues?

 

[cjard]

Once upon a time there was a wall with a large footprint bearing the load above. Removing a big section of it necessarily puts more load on the bits that remain, and it's not as spread out. That can cause things to shift, ground to compress a little more.. there will be a slight flex in the steel, it also has to be packed into place rather than being built on as if it were going from the ground up, so overall there's a lot going on. Things generally settle to their new locations and then stop..

The idea of cutting wedges out of e.g. A credit card (or something thicker if you have it and means to cut it) is that the cut sides run to a very sharp point, so you can get it in the crack - you want the edges you cut to be touching the sides of the crack. If it's really not big enough for even that, it's not a concern. Paint over it.

 

[^woody^]

The issue is whether the beam has been designed incorrectly and has deflected too much, or whether the installer has jacked the wall up too much, or let it settle too much.

Probablly the latter, but you never know.

It is going to take a while to settle down as the house will move slightlly with heating patterns.

Now that is cracked, no amount of filling will cover it, and it will always crack in that same place. So read up on repairing cracked plaster with mesh or sections of new plasterboard

Did the council inspector actually check the installation and the packing of the wall or just the beam size - as they typicaly would just do?