Securing existing joist binder – adding additional ones

[Makeitgo]

Hi all

I’m trying to make the loft ready for light storage but have seen that a few of the ceiling joists have pulled away from one ceiling binder. It’s a 1930s bungalow, so guessing this is due to movement in timbers and possibly joists being walked on over the years. The binder in question (Binder 3 in Floor Plan) is 6.4M long and it traverses two bedrooms with an internal wall supporting the middle of its span, but essentially the section with issues that spans Bedroom 1 is only 3.2M. It’s only the Bedroom 1 area I’m concerned with.

The binder is constructed from 2 lengths of 4 x 2 with one 5.2M length overlap joined to a second shorter piece. The largest section is still nailed down tight to the Joists over Bedroom 2, but it starts to warp when it gets to Bedroom 1, ending up with a 13° twist at its end, also probably contributing to the binder separating. The overlap joint also now looks a bit out of line/ropey also partly due to the twisting action perhaps. The worst gap between the binder and a one joist is about 28mm (# 4 in plan and ”B” in photo). There is also a deflection in the ceiling plasterboard underneath where the binder runs.

Luckily, I was able to get hold the floor plan which I’ve added all the joists and binders to, illustrating the layout pretty accurately. The joists are light brown and the binders are dark brown in the plan.

I was planning to install a couple of additional binders either side (marked in violate) to help stiffen the bedrooms' joists up before I realised this binder would be an issue. However, I now think sorting this binder out is priority before any additional reinforcement is added.

I know 4 x 2 joists spanning 4.8M isn’t ideal but it doesn’t seem too hollow sounding under foot and the joist centres are just under 400mm at 14 ¾”. I was reckoning that with two more binders and maybe some lightish 15mm ply as loft flooring to reduce flex, it might be adequate as it's not a habitable space.

Also, presumably if the suspect binder is under tension and acting to prevent roof spread, it would be an advantage to install the additional binders while the ceiling was still jacked up to “level”?

I’d be interested in anyone’s take on a good way to deal with this binder or anything else for that matter? In my head, I’m wondering if you’d be able to do the following:
(Please see Binder 3 Repair.jpg – new timber added is coloured green)

• Support (acrow up) the ceiling of Bedroom 1 from below along the line of the binder
• Cut the binder between joist 8 and 9 (where it’s only very slightly twisted)
• Remove the old section to the left of the cut (sitting on joists 1-8) over bedroom 1
• Replace the removed section with a new piece of 4 x 2 C24 with a sufficiently long overlap joint located above the central wall, using the appropriate fixings/hardware

The appropriate screws and brackets (as oppsed to nails) on all parts that need to be connected would prevent unnecessary vibration/damage to the plaster boards while carrying out the above.

Apologies for the mammoth post, but would appreciate your thoughts.

Cheers

General Background - It’s a Purlin Roof, 6 X 4 Purlins, 4 x 2 ceiling joists spaced at 14 ¾” running at 90° to the 4 x 2 rafters. There are two diagonal struts from the tops of central internal walls to near the midpoint of each the two longest purlins and two more struts at each end supporting the two shortest purlins in the same way. There is also one collar tie at each end of the roof. One end of Binder 3 is nailed to one rafter and joists 1 & 2, the other end, to one rafter and joists 18 and 19.

 

[Makeitgo]

I know this is a big post, but I was wondering if anyone might be able to give a couple of words on how they’d fix just the binder.
Maybe I need to replace the whole length? Am I a million miles out with my thinking on how the fix would be done (the bullets)?

Cheers all

 

[Deluks]

Just a few passing thoughts...any proper repair would likely involved damage to the ceiling below, and could result in cracks, potential redecorating/skimming.

The overlap on the binders (if I'm reading the plan correctly) is too long, the binder doesn't need to extend more than about 100mm beyond the supporting wall.
If it's been overlapped for strength (although probably wouldn't do a great deal) then it should have been bolted.

You could potentially cut through the nail that's exposed with a multitool or junior hacksaw, then try and jack it up using a C clamp, and a block of wood fixed to the side of the ceiling joist. Then reattach with a heavy duty right angle bracket.
Hard to see how much the other joists have pulled away.

There appears to be dampness on the end of the dodgy binder, might want to get chimney flashings looked at.

Fixing a whole run of 4x2's over the lot would be the best way to board for light storage.
Search the forum for "Boarding the loft for storage"

 

[Makeitgo]

Deluks,

Thanks so much for taking the time to reply. Just a couple of questions if that’s OK.

Just a few passing thoughts...any proper repair would likely involved damage to the ceiling below, and could result in cracks, potential redecorating/skimming.
I kind of expect that, but it would be good to try and keep the fallout to a minimum.

The overlap on the binders (if I'm reading the plan correctly) is too long, the binder doesn't need to extend more than about 100mm beyond the supporting wall.
Yes, the overlap on (dodgy) binder 3 is 106cm long and I think strength was the intention because the overlap is mid span. Regardless, the overlap joint has failed and no longer keeps the binder in a straight line (joint is nailed sparsely/badly as opposed to being bolted).

On my proposed fix (binder-3-repair-jpg) - I thought it might be more ridged to have a large overlap above the central wall, but then I ain’t no Brunel : - )

You could potentially cut through the nail that's exposed with a multitool or junior hacksaw, then try and jack it up using a C clamp, and a block of wood fixed to the side of the ceiling joist. Then reattach with a heavy duty right angle bracket.
Am I right, is this what you’re saying:
- Cut the nails, so they’re not obstructing the joists and binder from being pulled together again.
- Attach (screw?) some timber to the side of the joist that’s pulled away and use it as an “ear” to somehow purchase a “C” clamp on, then tighten the clamp threreby squeezing joist and binder together?
- Use “L” bracket to replace what was nailed together before.

Hard to see how much the other joists have pulled away.
I couldn’t upload all the gap pics when I posted, but here they are now.

There appears to be dampness on the end of the dodgy binder, might want to get chimney flashings looked at.
Yes, thanks, that’s definitely going to be sorted ASAP.

Fixing a whole run of 4x2's over the lot would be the best way to board for light storage.
Search the forum for "Boarding the loft for storage"
I’ll have a search, thanks.
As a matter of interest, do you mean run a load of 4 x 2s parallel to the binder to form a cross batten effect (i.e. 4 x 2s 90° to joists?)

 

[^woody^]

What's actually wrong with the binder?

 

[noseall]

What's actually wrong with the binder?

Looks to me like he could use a clamp or an Acrow or two, to prop the joists back up snug beneath the binder. And some fixings.

 

[Makeitgo]

Hi Woody,

There’s nothing wrong with it over bedroom 1 but in the longest section, there’s a twist in it starting at the central wall that ends up with it 13° out when the shortest section is nailed to it at the overlap. This has caused the overlap joint to have a gap in it (unless it was warped from day one). It looks like the knock-on has been that the joint is now at an angle exacerbating its sag. Please see my carp sketches of this angle, the twisted 4x2 and photos of the joint.
Apart from that, the end near the chimney has been a bit wet in the past, as pointed out by Deluks. I’ve poked a screwdriver into this bit and it still looks in a good state. I thought it might be sensible to just scrap the shortest section and replace it as per Binder 3.jpg My only reservation in cutting it, is that the binder might be under tension (preventing wall spread), so I’m still scratching my head a bit.

 

[Makeitgo]

Looks to me like he could use a clamp or an Acrow or two, to prop the joists back up snug beneath the binder. And some fixings.

I'm thinking acrows are the way to go, cheers noseall.

 

[noseall]

I'm thinking acrows are the way to go, cheers noseall.

If you concentrate the thrust of the prop under each joist, they should hammer back into position.

 

[catlad]

If it was my loft and I wanted to utilise it, I would floor it out in 18mm T&G OSB 2400mm x 600mm
using 4mm x 70 mm screws. Then add new binders where I thought needed.

 

[^woody^]

Dry plaster board or lath and plaster has very little tolerance for being moved back into position once its bowed over a period of time. The more of an area you try to lift up, the harder it will be.

For the binder joint, use a couple of m10 coach bolts with square washers, and tighten them gradually. They may not fully close, if so, just tighten to prevent further movement.

For the joist sag, the joist may or may not be able to be lifted up, but if it does move, then cracking of the ceiling is certain, and it may be loosened on the fixings too - or it may not give.
Or the joist can just be secured with some timber or couple of straps or brackets, if you can live with the ceiling as it is.

If you are minded to attempt to lift the binder and the joists as one, then prop under the binder joint.

For the damp timber, yes get the cause looked at, but once dried out it should be OK

 

[Makeitgo]

Woody, as ever thanks for the insight. I had a feeling this wasn’t going to be a picnic so I’m grateful for the advice. Another quick question, given the design, would you say that the binders contribute to countering roof spread? Not sure if they'd be under tension.
There are only two binders and apart from the joists, they are only nailed to one rafter either side at their ends. I’m presuming the diagonal struts and collar ties do the job mainly.

 

[Makeitgo]

If it was my loft and I wanted to utilise it, I would floor it out in 18mm T&G OSB 2400mm x 600mm
using 4mm x 70 mm screws. Then add new binders where I thought needed.

Thanks catlad. OSB yeah, I’ll probably end up doing something like that. I know it’s more pricey, but I was also toying with using 15mm ply to keep the weight down.