subfloor problems

[victerrace]

Hi.
New to the forum. must say that i wish i had discovered it sooner. An invaluable

resource.
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Was due to have new floorboards layed in the hall and lounge of my single story terrace in Melbourne. When the layers arrived they said that the bearers and joists were not up to the job. Though I had spent the 4 previous days attempting to level and sure them up they just weren't up to scratch. <o></o>
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The house is circa 1880's and the sub floor consists of bearers that have been layed on the ground, rested on brick or bluestone piers and packed up with just about everything imaginable. (including what looks like a VERY ornate and ancient support post that once held up a shop awning). But no stumps<o></o>
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I have had many suggestions about how to fix this.<o></o>
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1- A restumper told me that as there are no existing stumps I would be better off trying to do the job without stumps. Putting new bearers and joists over existing bluestone etc. Not a perfect job, hard to get level without a lot of 'dodgy' packing but should last<o></o>
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2. A builder/renovator who has done a few houses in the local area suggested that its actually quicker, cheaper and more effective (of course) to do it properly with new stumps.<o></o>
I am inclined to follow his opinion due to experience and the fact that he seems straight up, but have been told by a previous client of his that he overcharged them.<o></o>
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I suppose I'm just after any similar experiences and an idea of what a reasonable price would be for new stumps bearers and joists to go in. lounge room is 6.58x3.5m 22m2 <o></o>
hall is 1.1x7m 8m2 (but does not need stumps) here there will be ledger bolted to the brickwork and joists hung across.<o></o>
All the old material will be removed so who ever does the job can walk in and start stumpin' and joistin etc.<o></o>
Thanks<o></o>

[OBBob]

If the existing footings really are useless and there is room around them I wouldn't have thought it would be too hard or expensive to add new stumps if the old floor is cleared out.

I'm only a weekend warrior but I would imagine you or a builder need to
- Hire a two person post hole digger and dig new holes
- Buy some concrete stumps from cope (approx $5ea)
- Set the stumps on a pad of concrete (level the tops with string lines or a laser level)
- Lay new bearers and joists.

Also, there are a lot of high-tech timber and steel products out now that may enable you to get larger spans and reduce the amount of stumps you need to put in ... might be worth a look.

[victerrace]

thanks for that. These laminated joists I hear about (assume these are the high tech timber products you mentioned) are they available at most timber yards, bunnings etc?
Cheers.

[OBBob]

There are various types and profiles, the most suitable probably depends on the amount of vertical clearence you have. They are probably out of Bunnings league.

Best thing would be to talk to your local timber yard about what product is best for you. They may not be cost effective for a small job ... I don't know? Timber yards probably wont stock them but they would get them in a day or two.

Try to find a timber yard that deals with builders, rather than a generic hardware store ... they are more likely to have experience in this sort of thing.

[woodsprite]

Hope this helps. Our old house (about 55) had a large room added onto the back of it some time before I bought it about 30 years ago. About 20 years back I thought it time to replace the olf floor as it was pretty crappy and uneven and starting to get a bit springy. Local builder came to do it for me after I ripped upthe old boards (baltic, I still have most of them). Lo and behold, the few bearers that were there were sitting onthe ground!

Builder simply replaced them with decent hardwood numbers but this time levelled them and sat them on bricks and put down a new pine floor. This room is about 6 metres by 6 metres and the floor is as good today as the day he finished. It is pretty much a family room and gets a heap of use, and has an iropn frame piano sitting against one wall - not a sign of sagging, flexing, shifting, anywhere.

SO, I reckon if your underfloor stays dry, as ours does, my 3 cents worth is to go with putting new bearers pretty much onto the ground or the bluestone or whatever was there. I know a better job would be to put in stumps etc. but our floor has lasted very well without stumps.

Whatever you decide, hope it lasts well and doesn't cost too much.
Jeff

[andrew076]

I once did some plans where the owners ripped up all the old floor framing and poured a 'paving' slab throughout the entire house !

Dont know how it worked out for them. Has anyone had any experience with this before ?

[silentC]

thanks for that. These laminated joists I hear about (assume these are the high tech timber products you mentioned) are they available at most timber yards, bunnings etc?
Cheers.

You should look into Hyspan beams. They are an I-Beam made from ply. I used them in my place. A 170x45 will single span up to 3.6 metres with 450 spacings. If you sit them on a ledger you wont need stumps or bearers.

On availability, I got all my stuff through Mitre 10. I'm sure Bunnies can get them too. They don't stock it though because they are usually made to order.

[Tote]

I once did some plans where the owners ripped up all the old floor framing and poured a 'paving' slab throughout the entire house !

Dont know how it worked out for them. Has anyone had any experience with this before ?

If it was a victorian style house I bet they got themselves some rising damp issues in the walls.
Regards,
Tote

[Old Codger]

In Tassie we need 225mm clearance under any timber in sub-floor. This would apply to LVL as well. If the bearers need to be lower than this then treated pine would be the answer. If the joists need to be closer than 225mm then they should be treated pine as well. It would be a good idea to carefully examine the ventilation for this area as well. You probably would not be able to bring it up to BCA requirements but you may be able to help the problem significantly. Look at punching vents thru outside walls or thru to other areas that have ventilation.

[silentC]

I you use Hybeams then you don't need bearers for that span, so you actually need less headroom than you would with bearers and joists. If you use 170mm deep LVL then that's all the head room you need, so providing there is 400mm from ground to bottom of the flooring, you're OK. The Hyspan book I've got says that it can be used in sub floor apps providing standard practices for ventilation and clearance are followed. It's made from pine though, so it will rot if it is constantly wet.