Suspicious RSJ / floor joist attachment

[PlasterMike]

Hi there

I'm currently having some structural work completed at home. RSJs are in but I'm a bit suspicious of how upstairs floor joist have been supported. Basically the usual noggins have been wedged into RSJ and then another length of timber screwed to them. The upstairs floor joists are then just sitting on top of that length of timber.
Is this secure enough?
Advice would be very much appreciated.
Thanks in advance!

 

[KenGMac]

PlasterMike, hi.

I have severe reservations as to the method adopted to fully and completely support the first floor joists, it appears that the joists are being supported by just two nails into the noggins which them selves are simply lambed into the web of the RSJ.

Do you have a good drawing of how this connection should be constructed? My opinion is that the floor joists should be in some way [there are various options] be taken into the web so that the load applied on the joists are transferred to the RSJ, as above the load of the first floor joists are being transferred by some nails??

Have you discussed this with your builder, and more importantly what does your BCO have to say about this unusual configuration? suggest a phone call to the BCO may prove of value?

Ken

 

[PlasterMike]

Thanks Ken.

The existing floor joists were cut in the middle to allow this RSJ to be raised up rather than supporting from below (trying to hide RSJ in the ceiling below)
The final steel was put in on Friday so BCO and architect haven't seen it yet.
Will be contacting SE and architect tomorrow to obtain details of designs.

 

[^woody^]

The timber should be in the web of the steel, and the joists supported off hangers fixed to it.

Above all, the method of fixing and support should have been specified by the designer, not left to the builders to do what suits them.

 

[PlasterMike]

Thanks Woody

Will get details from SE that did steel calcs and design tomorrow.

 

[noseall]

We would have had holes drilled into the web and a timber sandwich fitted inside both webs and bolted through, doubling up if necessary. This should have been done before lifting the beam.

 

[hansPulesh]

the joists should have been trimmed and inserted into the web of the rsj as a lot of people have already said. Then noggins inserted between the joists to stop them bowing or moving.

The builder doesn't seem to have done it right from what I can see and I would get the inspector in as soon as possible.

It can still be saved though and as it's all open, quite quickly and easily. Speak to the inspector but he may be ok with lengths of joists (of the same size as what you already have) being bolted to the existing joists and inserted into the steel. If he is, get some calculations done as to how long the extra lengths of joists need to be. And please make sure that the builder bolts the new lengths of joist into place and doesn't just screw or nail them in place - otherwise your 1st floor will be in serious danger of collapsing as soon as you start putting weight on it (or maybe even before this!)

 

[^woody^]

the joists should have been trimmed and inserted into the web of the rsj

That can not be done. The joists have to be cut back to allow the steel to be inserted upwards. At best that must be cut to the width of the steel, and can not go into the web

 

[hansPulesh]

That can not be done. The joists have to be cut back to allow the steel to be inserted upwards. At best that must be cut to the width of the steel, and can not go into the web

Where I am BC like it done that way on one side and then like the joists on the other side to be extended into the web from the other side. Once done, Noggins put in place to stop any movement. This is similar but just that joists on both sides will need to be extended into the web.

 

[^woody^]

that joists on both sides will need to be extended into the web.

How do you extend joists?

 

[hansPulesh]

How do you extend joists?

Using more joists bolted on to the existing (but now shorter) joists.

 

[hansPulesh]

^^^^ To add, then inserting noggins between the extended joists to again stop any movement.

 

[r896neo]

Using more joists bolted on to the existing (but now shorter) joists.

This is a terrible idea.

The timber bolted into the web and hangers method mentioned by woody and noseall is the way any normal person would do it. The fact that the builder was happy with this arrangement is pretty worrying, its like he never even considered it before realizing the joist ends where floating in mid air. Which would imply he has never done it before...

If this was anything other than a temporary lash up its awful. The 2'' bearing isn't great and the full load of the floor is carried by the screws holding that 4x2 onto the little noggins. I imagine in time it could shear the screws.

 

[^woody^]

How do you extend joists?

Using more joists bolted on to the existing (but now shorter) joists.

That's not a very good solution, and I would be surprised if your BCO's favour this over other methods - which they can't really do, as they are not able to dictate how something is achieved, but rather just check that the end result is satisfactory.

 

[tony1851]

Thanks Woody

Will get details from SE that did steel calcs and design tomorrow.

Don't be too surprised if there aren't any details.