# Forum Home Renovation Sub Flooring  Strengthening saggy bearer

## bydant

Hi All,
I currently have an issue with one of the bearers in my house and have come up with a plan to strengthen it, which I wanted some sanity checking on. 
The bearer spans 3m and is sagging in the middle. Above it is the fridge, which I think is the cause, but due to the design of the house we are limited to placing the fridge in that area. 
The span of 3m is unusual and I think it is the result of a previous owner moving some of the stumps and partially supporting the bearer with a piece of train line. 
The sagging bit in question is after the rail line and is not supported over the 3m span. 
My plan is as follows: 
Jack up the floor joists using an additional temporary timber bearer to support the work area and jack up the centre of the bearer to get it straight, if it does not return to straight after the pressure is relieved. 
Bolt a 3000mm X 100mm x 50mm C-channel to the timber bearer with M12 bolts every 200mm
Remove the temporary support. 
I understand that there will be some cracking etc internally, but we will be refinishing anyway. 
Any advice appreciated.

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## Moondog55

Why not put in a couple of extra stumps instead

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## bydant

The soil is highly reactive and requires footings that go down 1800mm with reinforced concrete for the first 500mm. 
So if it is feasible, it will also be cheaper and less time consuming.

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## r3nov8or

I think I'd go with two stumps too, reducing the span to a much better 1m each, as long as there was enough clearence to dig decent footing holes at least 600mm deep (absolute minimum). 
If you go with the c-channel, consider so many holes will reduce its capacity/strength (but I can't find anything official), and also reduce the capacity of the original wood bearer (AS1684 limits such holes to 3 holes per 1800mm of span), so you'd have to up the dimension of the c-channel/PFC. Also, what is the distance between bearers? - this will help spec the PFC. It's probably simpler to spec the right PFC for the job without all the holes but then you have to assess whether 2xM12s at each end through the bearer (above the stumps) would be enough support or whether it would need support on its own stumps, in which case you'd be digging two stump holes anyway...   
Yeah, a couple of stumps are sounding better... 
EDIT : just saw your update. Stumps are getting harder then... what are the stumps made of? Thinking you may be able to add to the side of them to support the PFC at each end.

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## Moondog55

Hmm? OK so this is just Thinking out loud" and needs an expert opinion but
What about an LVL beam of the correct width and depth to span 3M lots of builders glue between them and bolting plates at each end and in the centre and 12mm gal bolts?

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## r3nov8or

I swear you have shares in buldiers glue companies, Moondog  :Smilie:  
I'd agree an LVL is an option if there is enough/compliant ground clearance remaining.

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## bydant

There is about 1800mm ground to bearer clearance. The stumps are 200x200 concrete. The bearers are spaced at around 2500mm. 
There would be enough space on the top of the stump to accommodate  the PFC. 
So with the AS1684 I would be looking at max of 4 bolts.

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## r3nov8or

Have a read of this and take a look at the first span table on page 7 here http://www.edconsteel.com.au/pdfs/in...el_housing.pdf 
I'd be using a 125PFC. 3m Load Width for a 3.5m span. Supported on the current stumps is great news.  
In the back of my mind is the fact that the current bearer is actually doing a job (not a great job, but a job nonetheless) so going overboard is probably overkill, but a 125 would be peace of mind. 
Out of interest, what are the dimensions of the current bearer, and do you  know what type of wood and grade it is? 
LVL is still an option if its height  can be supported on the stumps - minimal notching over the stumps would probably be OK too. 
EDIT : Caveat on the linked doc is that it is based on "300PLUS" grade steel

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## bydant

Not sure what the wood or grade is. It is around 100 years old though. Dim is around 120 x 90, but would have to confirm.

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## r3nov8or

> Not sure what the wood or grade is. It is around 100 years old though. Dim is around 120 x 90, but would have to confirm.

  Looks like placing a 125PFC on the stumps is going to be a squeeze, and a suitable LVL even less likely. 
While you are under there, also advise the dimensions of your joists. 2500 is a hefty joist span for 100yo 'technology'

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## bydant

Found some engineering docs:
FJ 125 x 50 @ 450 centres
Bearers 125 x 75

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## Moondog55

5inch X 3inch was /is the standard bearer size, sounds like it is/could be  stump missing that really needs to be replaced, so is the original hole? Broken stump? in there somewhere??
I'm thinking my initial idea is the way to go or maybe you could use a deeper section but thinner timber on either side of the existing bearer, just ideas and you need an expert opinion of course before you go ahead.
how much room on either side of the bearer do you have? if the bearer is 75mm and the stump is 200 there could be 60mm on either side or 120mm on one side for instance

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## Bloss

Sure is that stumps have been removed. I'd be adding back a stump or two and given the soil type be more inclined to make a wider pad rather than go deeper. In fact simply a couple of pre-cast (reinforced) concrete slabs - say 400x400 or 500x 500 sitting on a levelled area and stumps to suit. Why over complicate - as r3nov8or says the bearer is working so just needs some extra. My view is keep it simple - a bit rough and ready, but it'll do the job. If you are concerned about later soil movement use a pair of wedges on top with a screw to hold when levelled and you can remove the screw adjust as needed.

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## ringtail

Hey, I haven't said anything, yet :Biggrin: . I will however throw my 2c in. I would go the 125 PFC bolted at 600ctrs after pushing the bearer up and even putting a bit of pre-stress in it.

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## Bloss

Nah - way over the top IMO . He has a little sag because stumps have been removed and he's bunged a fridge over the centre 100yr old 120x90 (or 5x3 if that's what it is) ain't gunna break. Fair chance it ain't gunna straighten either and I wouldn't be bothering cutting to relieve it. So mainly trying to just remove the worry - whack a cuppla supports under there . . . 
Of course is OP wants to go the full monty and bung beams and bolt it on etc why not - but he's gunna find it hard to fit 125mm deep beam in a 120mm space over the concrete stumps. . .   :Redface:

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## bydant

The bearer is 125mm, so a 125mm PFC will fit fine. 
All up, I am looking at $150 for equipment hire and parts. 3 hours of labor on top and I'm done. 
This is the way I look at it:
Extra stump: 1x 2.8m 200x200 stump ($60?), Have to dig a hole and maneuver 60kg+ stump, jack up the bearer ($50 equip), plum/set height 
PFC: 1x 3m ($80 cut to length) 6x m12 bolts and nuts ($20), jack up bearer ($50 equip) maneuver 35kg beam, drill and bolt  
In the end the full monty is pretty comparable to the stump in time v effort v cost :Smilie:  And I don't have to dig holes, I just get to drill them!

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## intertd6

another solution is to use a barup rod. 
regards inter

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## Cecile

> I swear you have shares in buldiers glue companies, Moondog

   :What he said:  
*eyeroll* 
heaven forbid we ever try to undo anything he's ever built in this place!

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## ringtail

> Nah - way over the top IMO . He has a little sag because stumps have been removed and he's bunged a fridge over the centre 100yr old 120x90 (or 5x3 if that's what it is) ain't gunna break. Fair chance it ain't gunna straighten either and I wouldn't be bothering cutting to relieve it. So mainly trying to just remove the worry - whack a cuppla supports under there . . . 
> Of course is OP wants to go the full monty and bung beams and bolt it on etc why not - but he's gunna find it hard to fit 125mm deep beam in a 120mm space over the concrete stumps. . .

  Just notch the PFC. extra stumps means blocking valuable walking and storage area . At some stage someone did the same thing to my house. Removed the centre stump and just bolted another bearer to the existing. Now they have PFC's bolted alongside and I get to keep my clearway. Of course, its not legal height at 1850 but all totally usable with a slightly bent neck

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## bydant

> another solution is to use a barup rod.

  What is a barup rod?    

> heaven forbid we ever try to undo anything he's ever built in this place!

  As a general rule, I only use glue as the last resort, as I know that the next time it breaks or needs to be worked on, it is going to the tip!

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## Cecile

> As a general rule, I only use glue as the last resort, as I know that the next time it breaks or needs to be worked on, it is going to the tip!

  Moondog's hysterical at this post.  He said, tell him that nothing I ever fix breaks.  You should have seen him (and five friends) trying to demolish a pergola at a rental we once had.  Yep...liquid nails wins again.

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## intertd6

> What is a barup rod?

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## Bloss

> Just notch the PFC. extra stumps means blocking valuable walking and storage area .

  My interpretation was that the OP wasn't trying to retain the space for use he was concerned about the sagging due to the fridge weight (and presumably that is noticeable from inside)- the objection the OP had to the stumps was soil type and all that digging - none of which is needed. 
If the underfloor space _is_ wanted and as open area then PFC would be fine - but for this type of reinforcing support use 100mm 100 PFC Steel Data and no notching needed. 
I was trying to offer the least effort fix - aside from the really least effort: just leave it as is - it seems an aesthetic issue since there is little likelihood of catastrophic failure or even increased sagging . . .

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## ringtail

Just prop it up with milk crates then  :Biggrin:  :Biggrin:  :Tongue:

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## barney118

I think you are wasting your time and money. As bloss has pointed out, you will struggle to straighten this beast of a bearer without crippling the bearer and stumping under it which IMHO will weaken what is already there.
 I have similar bearers which I have tried similar and I am not happy with the outcome. I have bolted 150 LVL's next to existing bearers, under the joists that didn't span the whole area (2.5m) that were sitting on rail lines (which I removed). When you start jacking the whole thing will move and lift of its existing stumps. Assuming there was a stump there before? have you scratched the surface to see if there is a pad there? I would consider pad/stump and wedge if the footing moves in the future.

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## bydant

After doing some more investigation last night I discovered that the bearer is not sagging. 
The row of stumps that the bearer sits on consists of 3 stumps with a railway line sitting on top (as a supporting beam) supporting the bearer with a span of 7.1 meters. this is followed by the section of bearer in question, 2 more stumps, which are in the correct level position, which support the remaining 4.2 meters. 
The section supported by the rail line starts at the correct height, but is at least .4 of a degree off horizontal, leading to a drop of around 45-50mm. 
So to correct this issue I will need to fix the previous 2 stumps.

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## Bloss

> Just prop it up with milk crates then

  Whatever works eh!   :2thumbsup:  :Wink:

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## Cecile

Every time I see the title of this post, the devil on my shoulder tells me to post something...ummmmm...unsavoury.   :Yikes2:

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## Bloss

No need to mention moondog then . . .    :Wink:

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## bydant

> Every time I see the title of this post, the devil on my shoulder tells me to post something...ummmmm...unsavoury.

  I know what you mean. Saggy is just on of those keywords. 
Thanks for the replies and help guys. 
I think I will break out the water level and pack some of the stumps with fibro until I have time to replace the problematic stumps..

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