"settling"

[Steve]

My mum has recently had a wall knocked down between the kitchen and dining room. This wall is shown in red. Downstairs the whole space is now open plan (there are other rooms but i havent shown these for simplicity)

Upstairs, there are a couple of thermalite walls which were built onto the floorboards (next door had their ceilings removed, and I saw how one of his walls wasnt even on a joist, the boards were all slightly bowed). These upstairs walls are shown in blue. The upstairs doors are in orange.

Anyway, its been a couple of months since the work, and now a couple of the doors wont shut properly! The bathroom door is missing its strike plate, so wont latch shut. Also there is a couple of cracks along the thermalite walls, only in the corners and along the top.

Any advice? The builder used a lightweight lintel (one of those hollow box things), about 100wx200h positioned below the joists at a section where the joists overlapped each other. At one end (the party wall) the lintel was recessed into the wall, at the other (staircase end), they left a pier onto which they sat the lintel.

Untitled

• Steve
• 28 Jun 2012
• 1

 

[^woody^]

You don't say what that new lintel is actually supporting?

Anyway, there should be no settlement of anything above, because that as already taken place from when built. The new support should hold up whatever it is holding up in its existing position and not allow any movement or settlement

Some minor cracking may take place just as a consequence of all the banging about, but nothing like the wall cracking or door misalignment you describe

 

[tony1851]

How far into the party wall did they set the beam? Did they put it on a padstone? If it's only resting on a lightweight block, and not set far enough in, its possiblle you have local crushing of the blockwork, with consequent settlement.
Why did they use a holllow box? These can distort at the ends if not set in with sufficient bearing length.
Most builders would have used a conventional steel 'I' beam.

 

[Steve]

The lintel is supporting the upstairs floor at its centre point, as well as the thermalite walls that rest on it. The thermalite walls also take some of the weight of the upstairs ceiling - the roof is a plain triangle in cross section, not a self-supporting structure.

The beam is sat on brickwork at both ends. The house is 1940's so has solid brick walls apart from the upstairs dividing walls. However, the walls to the right and top of the stairs as you look at them continue up to the upstairs ceilings. These are solid brick.

As far as I know they knocked out a whole layer of brickwork from the party wall - so its sat in about 4-5 inches, and the same at the other end.

Should the box lintel be strong enough for this? Dimensions I'm not sure of, but its about 3-3.5 metres span, with the above loadings.

 

[^woody^]

This should have been done via a building regulation application and checked by the council. It does seem a significant load for a box lintel

 

[theoldun]

Steve, Mums are Mums, and you are in the right department.
Just clarify a couple of points please.
Measure the exact width of opening that has been created.
Measure the inside width of house back to front.
Joists run from front to back and sit on wall marked red?
Was there, or is there a wall above the wall marked in red?.
Are there any other partitions to first floor except those shown in blue, making house a two bed and bathroom?
Woody is correct, should have been done on building notice.
Give us the answers son and will help you out.
Regards oldun