100mm bearing ok ?

[John Wardle]

Hi wondering if a 100mm bearing is ok for steel to sit on . Builder is looking at putting 8x4 rsj straight into internal wall which would only have 100mm bearing then. Span is 3m the rsj will be under floor joists an there is a wall above and in loft there is block that roof timber sits on.

 

[tony1851]

As long as there is a decent spreader, sitting the beam onto the inner skin is fine.
What some buiders use is 6" x 4" precast concrete lintels cut to size with a disc cutter.
The length of the spreader required depends on the load the beam is carrying, and the type of blockwork/brickwork on the inner skin (eg lightweight block and hollow cinder blocks are not too strong and will need a longer spreader than dense concrete block or common brick. Your SE would advise.

 

[John Wardle]

Hi Tony
I was told to use a windpost an dig down to foundation to sit on an bolt into wall. Then connects to 8 x 4 rsj . Which found was daft. Builder has said rather put in wall

 

[tony1851]

It was your building inspector who told you to install a post, was it not?
As you are paying him for the service, and yet he is demanding soomething extra, you need to ask him to justify precisely why he wants that because that is really the SEs job.
The inspector is probably just going by the 'rules of thumb' in the guidance to the Building Regulations; those rules can be avoided by proving an alternative would be satisfactory.
Either get your SE to prove it doesn't need a windpost; or get used to seeing a big useless thing on your lounge wall.

 

[John Wardle]

Yes but I've had another se come in an has said what is that post never seen anything like this before. Said why is it not straight in wall. Really question if he actually new what he was doing. As said builder said he will take it out an go straight in wall

 

[John Wardle]

His reason for it is lateral stability

 

[John Wardle]

Back of house. Wall is between patio an single door

 

[John Wardle]

Similar plan to mine. Blue square is where there is 2 blocks in loft at top of this wall with the roof beam resting on that runs through the 2 houses

 

[tony1851]

There's a decent length of wall between the kitchen and lounge doors, so no worries about the wall being able to take the vertical load from the beam.

The inspector raised the issue of lateral stability, possibly because your floor joists seem to run parallel to the wall rather than into it (if they run into the wall, they provide some lateral restraint to the wall in high winds and help prevent the wall being sucked out). His reasoning is probably that the ground floor wall acted as a buttress support to the rear wall.

Two things come to mind; if the wall between the bedroom/bathroom(?) upstairs is a load-bearing wall, that will - or should - be bonded to the external wall and will give a degree of support. Second, if you got some metal restraint straps screwed to the underside of the floor joists and the rear wall - equally-spaced along the wall - that would give a mechanical fixing to the wall (surprising as it may seem, floors are often depended on to give support to walls due to their inherent rigidity).

Perhaps put that to your inspector and see if he will agree to that?

 

[John Wardle]

Hi Tony
Thanks for explaining some details. This is how the joists run in the house

 

[tony1851]

If that's the case, just fix 2 or 3 straps to the joists over the kitchen and screwed to the outer wall.
Can't see what the inspector's bothered about?

 

[John Wardle]

Any suggestions how this could be fixed. Don't think it's been propped properly door frame has dropped a little aswell