How to strengthen badly Notched Loft Joists (Ed.)

[Flembot]

Just had an oil to gas conversion done.

The company who carried out the work notched my 100mm loft joists pretty badly in this location of my loft, as you can see in the photo.
I have raised this with them and they are getting in touch with a joiner in order to put all this right.

Question - what sort of methods / techniques should be used here to repair or re-inforce these notches?
The pipes will need raised in order to run above the joists. Yes?
Down the line I want to replace all the loft insulation and achieve 300mm depth or equivalent - should I factor this into the equation when instructing work?

Thanks in advance

 

[noseall]

Just had an oil to gas conversion done.

The company who carried out the work notched my 100mm loft joists pretty badly in this location of my loft, as you can see in the photo.
I have raised this with them and they are getting in touch with a joiner in order to put all this right.

Question - what sort of methods / techniques should be used here to repair or re-inforce these notches?
The pipes will need raised in order to run above the joists. Yes?
Down the line I want to replace all the loft insulation and achieve 300mm depth or equivalent - should I factor this into the equation when instructing work?

Thanks in advance
View attachment 364876

Jeezuz effing Christ!

Those joists are doing two jobs and both are in jeopardy. Don't pay out a penny until the joists are fully reinstated.

 

[tony1851]

Cut an 8" long by 0.25" deep notch each side of the plumber's cut-out.

Get some 30 x 5 steel straps from the builder's merchants (or B&Q/ Wickes etc). They are pre-drilled with lots of holes.

Cut appropriate lengths of strip and screw down with three 50mm x 5 or 6mm screws each side of the notch. You'd need to countersink the pre-drilled holes.

Disadvantage of this is that you won't be able to screw the boards down over the strips, but the steel will compensate for the loss of the timber in the notch.

 

[Flembot]

Cut an 8" long by 0.25" deep notch each side of the plumber's cut-out.

Get some 30 x 5 steel straps from the builder's merchants (or B&Q/ Wickes etc). They are pre-drilled with lots of holes.

Cut appropriate lengths of strip and screw down with three 50mm x 5 or 6mm screws each side of the notch. You'd need to countersink the pre-drilled holes.

Disadvantage of this is that you won't be able to screw the boards down over the strips, but the steel will compensate for the loss of the timber in the notch.

I really appreciate the little drawing .pdf that you attached. I'm a visual learner so I really appreciate having this.

My thinking is:
1. Lift the pipes
2. we do what you have outlined in the pdf drawing that you attached, steel straps, 6mm notch etc.
3. Place boarding over the top of this area whilst straddling the steel straps
4. Fix the boards to the joist using counter sunk screws
5. Run the pipes along the top of the boarding and then down through the board and down through the ceiling

Pending a closer look by the plumbers/joiners - does this at least sound like a potential workable plan?

 

[Ivor Windybottom]

The metal plate looks like a very good idea.

Think I'd add a row of noggins either side of the notch too, just to add rigidity and help all the joists support each other.