Proposing a self-build floor level fixing in a loft conversion project

[KAZAAD]

Hello all,

 

I need some advice from builders, surveyors, engineers, architects or even self-builders, 

 

I am proposing a self-build on raising the floor level after the builder failed to follow the structural engineer's details by wrongfully installing the steel beam and timber joist upside down. You can see the drawings and photos where this has caused issues with the builder, who has refused to do the work as he wants extra money, and the engineer, who has not answered my queries. Building control couldn't provide their answer, so I had to create proposed detailed drawings for raising the floor level. 

 

I am so keen to do a self-building project on this issue. Is it worth it? Are these drawings suitable for raising the floor levels? I am open to ideas and suggestions. 

 

I have attached my documents just in case.

 

Kind regards

SE Detailed Drawing.pdf Sheet 1.pdf Sheet 2.pdf Sheet 3.pdf Sheet 4.pdf

[JohnMo]

Wouldn't the simple answer be to get builder, to add packers to the existing joists to bring up to level needed?

 

Your solution looks complex and maybe needlessly so, and maybe more costly than it needs to be.

 

The above assumes the joists are per drawing spec.

[markc]

 

easiest fix is to sister each joist with the tops levelled as you require

Edited April 7 by markc

[KAZAAD]

2 hours ago, JohnMo said:

Wouldn't the simple answer be to get builder, to add packers to the existing joists to bring up to level needed?

 

Your solution looks complex and maybe needlessly so, and maybe more costly than it needs to be.

 

The above assumes the joists are per drawing spec.

 

I cannot trust builders nowadays with their quotes. If I am going to add packers, would I need an engineer to check if its okay to place them on the existing josits?

[KAZAAD]

1 hour ago, markc said:

 

easiest fix is to sister each joist with the tops levelled as you require

 

Do you have examples that shows this procedure?

[JohnMo]

37 minutes ago, KAZAAD said:

cannot trust builders nowadays with their quotes

Should be free, they f*cked up and did it incorrectly - if not just with hold £xxxx from final bill, and issue them a bill if you fix it 

[Temp]

I also wouldn't do it the way you propose. Go with packers or sistered joists..

 

Packers: How level are the tops of the joists? If very level the you can probably buy packers or get them cut to the right height. If the tops aren't level go with sistered joists.

Sistered joists: These would probably be a similar size to the existing joists and fixed to the side of them. The advantage is you can clamp each one at the right height before fixing them in place. 

 

First thing I'd check is if the builder used the right size steels and fixed the steels together as specified by the SE. Then check if the joists the builder fitted are dimensionally correct (just installed too low). If both of the above are OK then I think you should be OK without new input from the SE. 

 

If you are parting ways with the builder I think I would invite the BCO to do an inspection in case there are other problems. Take notes and send the BCO an email to confirm what you discussed/agreed about fixing them. Then write to the Builder registered post with a list of defects giving him "opportunity to rectify". Say two weeks to build fix the defects without further funds. Meanwhile carefully work out the extra cost of fixing the defects (only) for any court claim.

 

BCO aren't always willing to give advice in writing for insurance reasons but might be more forthcoming verbally on site. 

[KAZAAD]

On 08/04/2025 at 14:37, Temp said:

I also wouldn't do it the way you propose. Go with packers or sistered joists..

 

Packers: How level are the tops of the joists? If very level the you can probably buy packers or get them cut to the right height. If the tops aren't level go with sistered joists.

Sistered joists: These would probably be a similar size to the existing joists and fixed to the side of them. The advantage is you can clamp each one at the right height before fixing them in place. 

 

First thing I'd check is if the builder used the right size steels and fixed the steels together as specified by the SE. Then check if the joists the builder fitted are dimensionally correct (just installed too low). If both of the above are OK then I think you should be OK without new input from the SE. 

 

If you are parting ways with the builder I think I would invite the BCO to do an inspection in case there are other problems. Take notes and send the BCO an email to confirm what you discussed/agreed about fixing them. Then write to the Builder registered post with a list of defects giving him "opportunity to rectify". Say two weeks to build fix the defects without further funds. Meanwhile carefully work out the extra cost of fixing the defects (only) for any court claim.

 

BCO aren't always willing to give advice in writing for insurance reasons but might be more forthcoming verbally on site. 

 

BCO have visited and recommended a packer hoisting procedure. He inspected the steel beams, which were okay, but he noted that the spreader plates for the rear steel beams at the loft level were installed on thermal blocks with weak bearing capacity. He suggested replacing one course/layer of thermal blocks with 10 N concrete blocks below the spreader plates. The structural engineer has noted this recommended but the builder did not follow. With the builder's dispute, is it safe to use at least two acrow props with strongboy attachments placed just below the steel beam to insert the 10N concrete blocks without needing a builder? 

 

If this is not the best topic to ask this question, I would move this question elsewhere. 

[Nickfromwales]

4 hours ago, KAZAAD said:

With the builder's dispute, is it safe to use at least two acrow props with strongboy attachments placed just below the steel beam to insert the 10N concrete blocks without needing a builder?

This is very dangerous work, and needs to be executed properly and robustly. You should consider getting another builder in to help you or to just do the work for you, it's really not something you should do under duress, or consider doing in ignorance of just how badly this could go eg if a prop shifts.

 

Death is permanent, and you don't sound to me like you are capable of doing this if I can be honest with you, plus that's a beast of a bit of steel with a huge amount of downward force now resting on it.

 

I'd be leaving the blocks, and installing a 6x4" concrete lintel on flat instead of the bricks. Ask your BCO if that is acceptable as I'd rather that option vs starting to disturb the wall and the surrounding courses of the fragile friable thermal blocks and the dry mortar. You can then pack the lintel up to the steel and do away with the steel plate (all needs confirming before you do a single thing of course!!).

 

You're looking at a minimum of 4 props, with the heads tek-screwed to the outer edge of the steel beam so they can't slip. Bases drilled and fixed with concrete anchors. If that comes down the rest of the roof will come down with it.

[Temp]

5 hours ago, KAZAAD said:

BCO have visited and recommended a packer hoisting procedure. He inspected the steel beams, which were okay, but he noted that the spreader plates for the rear steel beams at the loft level were installed on thermal blocks with weak bearing capacity.

 

Is it my imagination or has the builder used metal plates under the steels to spread the load? 

 

I think I'd ask an SE to take a look.

[Nickfromwales]

As for the carpentry (  ), did the guy have a chop saw, or was there just a very angry goblin, head held firmly in a vice, that he tormented and then offered the wood up to so it could be angrily gnawed into odd angles and shapes?

 

Or did he work at night without a torch?

 

The cuts and quality of the work is embarrassingly poor tbh, but not irrecoverable if you employ someone decent to come behind and put a few (lots) of the bad bits right. I particularly love the way that the short noggin was not replaced with a correctly sized bit of wood, but instead the gas nails were used to bridge the gap; at least he had the good conscience to use twice the number of nails to make up for the lack of feckin wood......  

 

Have you paid this goon fully, or do you have money withheld to give to another company to sort this all out? Best to continue forward with a new contractor, but if you want to DIY the carpentry then I guess that's not impossible, just a lot to do and you have to ask yourself if you are a) capable, and b) know what you are doing.  Not a dig at you, just a sensible, sober reply.