Builder knowledge question. Rsj/ load bearing wall/underpin

[Bouba]

Many a times diyers have removed internal wall to fit RSJ from the helpful advice on this site. What many have either failed to answer, or point out that the foundations of internal wall nibs are sufficient or not.(if the whole wall is not being taken out).

What is the right way of checking it out. How to dig test holes and what to look out for. How does one actually establish if the nibs are able to take weight of RSJ and upstairs wall and joists.

Please advice. The wall in question is in a 1930 victorian end terrace with 7x4 rsj with 55cm nibs either side.

Thank you.

 

[Skimmers]

NIBS?????
you mean pad stones????

depends on the building regs some ask for concrete block and others ask for 400mm long concrete lintels beded on a building sand mix with steel shims

min pad size is 150mm load bearing.....
No steel work should be done with out building regs and structural engineer calculations.

done loads of steels from door openings to full on RSJ steel works to open up the side of a pub
nothen gets done with out structural engineer calculations first....

Not having a moan but any one trying to fit steels ect with out the propper regs ect are just asking to be shot in the bum

 

[Bouba]

By nibs I mean pillars from the current wall. How does one know the pillars left from the current wall will be sufficient to take the load of Rsj and upstairs wall.

This is an opening in a load bearing wall for only 2.3 metres. The total wall size is 4 metre.

 

[RonnyRaygun]

By nibs I mean pillars from the current wall. How does one know the pillars left from the current wall will be sufficient to take the load of Rsj and upstairs wall.

This is an opening in a load bearing wall for only 2.3 metres. The total wall size is 4 metre.

The pillars should be designed/checked by a structural engineer, as should the foundations.
Calculations can be done to ascertain the strength of a nib and whether the allowable load will be exceeded.
Shallow foundations on poor ground might also have trouble spreading the load sufficiently to the bearing strata.

Although, from the dimensions that you have given, I can't see either being a problem.

 

[Skimmers]

soo the wall is 4m long and you only want a 2.3m long opening??
peace of **** then youll probs need concrete block as pabs and 2.6 long steel

 

[tony1851]

soo the wall is 4m long and you only want a 2.3m long opening??
peace of p**s then youll probs need concrete block as pabs and 2.6 long steel

He shouldn't use concrete blocks as padstones - they're not strong enough to take the concentrated load from the beam.
Proper padstones are made from high-strength concrete and intended as such.

With a wall 4m long and opening 2.3m, the remaining piers should be OK. If the brickwork is reasonably well-bonded, the load will spread downwards and outwards as it goes down the pier and into any adjoining walls. By the time it reaches the footings, it shoud be acting over a relatively large area and should be satisfactory, subject to no unusual ground conditions