Widening a door in a load-bearing wall

[Israelle]

Hello all, first post and would really appreciate advice from someone more knowledgable than myself!

We're looking to widen the door between our lounge and dining room to house French doors and side panels (hole would be in total about 2100mm) The original door has been bricked up and a new door opened in the centre of the wall. each door has a seperate concrete lintel and there is a pillar about 300mm across supporting the end of each one.

We've had a couple of builders over who have quoted around £1300 for the work (no finishing, just the hole and a new lintel) and that's way more than we're willing to pay! So we're going to do it ourselves. I've contacted the council and am just waiting for the info regarding the Building Control Order. Just a few questions that are bugging me:

1. Could we do it with a concrete lintel (as one builder suggested) or would a box-steel or RSJ be a better bet?

2. Should we go for a 2400mm lintel which would allow 150mm support each side or should we err on the side of caution and go for a 2700mm?

3. Will we need official calculations from a structural engineer for the BCO to approve the work?

4. Should we remove the old lintels (as I feel inclined too) or simply put the new one above the old ones (as one of the builders suggested.....)

And here's a picture for you to peruse (afraid I don't know how to make it bigger but it's annotated if anyone gets a chance to see it full sized!):

Lounge wall

• Israelle
• 28 May 2008
• 1

 

[noseall]

as a rule of thumb, any openings greater than 1.8m require calc's, even when using proprietary pressed steel lintels.

i would not feel comfortable using p.c.c. lintels over any loadbearing wall greater than 1.2m.

150mm end bearings is adequate.

regards the old door and lintel, i would have to know how it was constructed to form an opinion. there may be a can 'o' worms at this location.
there could be load issues here.....?

 

[chessspy]

ok,
the DS will probably insist on steel I beam.
However in reality it depends to some extent if the bedroom floor joists rest on the central wall or if they run side to side.
you can check easily by looking at which way the floorboards run in the bedrooms as the joists go at rightangles to the way the boards go.
In any event it will all rest on the DS (building inspector) do a sketch including as many details as you feel ok with, try a free program like mydeco.com or sketchup or similar.
I would say that 225mm would be more than adequate as a land. put it on a padstone about 18" long if at all possible.
take out all other lintols if possible and put the lintol as high as possible, forget the doors as you will never use them.