Floor lifting up bearers

[Pulse]

Hopefully Trevor or someone can help me here.
My brother just had a new blackbutt floor laid secret nailed and glued with ultraset. A few things were done wrong:

1. The boards were left to acclimatise in a big bundle.
2. the plasterers had finished a few days prior.
3. the house was not weather tight as flashings were missing around some of the windows and no archs around windows yet.
4. no expansion gaps

It down for a week or so and the whole floor lifted such that the bearers in the middle of the room were lifted off the stumps. There is now a 20mm high bow in the middle of the room. He then had a $2000 subfloor ventilation system installed in the hope the floor will just settle down onto the stumps.

What should he do? I think accept it, pack the bearers and live with it but he wants to move in, leave the floor uncoated and sand them in about 6 months when (and if) the floor drops onto the stumps.

Looking forward to some good advice

Cheers
Pulse

[journeyman Mick]

Pulse,
was there a builder or was your brother organising it himself? Either way the flooring contractor should have known better. I don't think I could live with a "fix up" here and I doubt that there would be a successful fix anyway (but would be happy if there was). Time to talk to the builder/flooring contractor/state licensing body :( .

Mick

[echnidna]

The floor might come down again in a few months but its probably stuft as a polished floor.

The boards have swollen so much the edges have crushed slightly. When the boards dry out they will shrink. He will have (probably minor) gaps between the boards because of this.

There are 3 possible solutions
Fit new flooring
Let it dry out and see what happens
If hes unhappy then , lift the old floor and relay it
As long as theres enough room left in the grooves to accommodate a tight fit for the tongues this might work. This would be best done in the mid to late dry season (summer?)

Why did he install plaster and floor before the house was weatherproof?

[glock40sw]

G'day.
get the boards out from the 2 edges of the floor ASAP.

This will give the floor breathing space.

Even if need be, pull a board out of the centre of the floor.

The expanded floor is putting pressure on the walls. It Can and will destroy the wall to floor construction integrity.

Is there wet soil under the floor?

Is the house water tight now?

Measure with a steel tape, the total of 10 boards. this should be 800mm for 80mm cover width boards.
If your are getting 801 802 that is OK.
If you are getting 806 to 810 it's not good.
If you get 810 to 815, pull out boards ASAP.

Do not say she'll be right. It won't.

How long has this floor been like this?
Where is the house?
Is it a level block or sloping?
Is the perimiter of the subfloor enclosed?
Is there any cupping in the boards?
Is there access under the floor?
You can get under the floor and spray paint the underside with any old oil based paint. This will seal off the board bottoms from the subfloor environment, Thus allowing the board moisture contents to normalize and the boards to return to a cover width close to the as installed dimensions.

You may need to install perimiter drainage to stop water getting under the floor.
Is there water staining on the boards? (black stain)

Let me know.

[glock40sw]

P.S.

Is it my timber?

where was it bought from?

[Pulse]

Thanks guys,

Trevor, I'll find out where it came from it has two longitudinal grooves on the bottom (?to stop cupping) it is actually 108mm wide (yep and secret nailed!). The house is a cavity brick semi in North Bondi with about 300mm subfloor space over sand. There is a rear courtyard with no drainage so that becomes a sump in the wet weather. The house is enclosed now with an large ducted A/C. The house is on a flat block. The subfloor access is through a manhole in the floor, it si difficult.. flat out on stomach crawling on elbows. There are a few vents but there is a flash new ducted ventilation system now with new holes punched in the external walls. There is no visible water staining on the floors either.

Bob, I'm not sure why the builder didn't get the place waterproof and sealed prior to flooring or plastering. Not wise really..

Mick, He subcontracted the flooring seperate to the builders quote.... I think the builder suggested it that way? maybe to avoid having to insure it?

I didn't really think of the pressure on the outside walls... that could really bring the place down as a worst case scenario. I crawled around underneath and the bearers were about 10mm off the stumps, I'm not sure where the other 10mm came from unless the stumps were 10mm out to start with...

I'll pass on the advice and find out some more..

Thanks once again guys
Pulse

[journeyman Mick]

Very good point about the pressure on the walls. I worked on a big resort job about ten years ago that had parquetry on concrete. Exterior walls were concrete block with a steel stud and track wall, gyprock lined, built about 50mm inside it. The parquetry bloke was real careful, moisture tested the concrete in several places before installation. Unit was closed off to other trades after flooring was laid and the ac was kept running over the Christmas break to keep the humidity constant. Of course Murphy struck and the ac developed a catastrophic failure that dumped buckets of water all over the flooring :rolleyes: . The parquetry expanded so much that it formed waves about 150mm high and pushed the stud wall back against the blockwork and crushed it :eek: .

Mick

[KevM]

Thanks guys,

Trevor, I'll find out where it came from it has two longitudinal grooves on the bottom (?to stop cupping) it is actually 108mm wide (yep and secret nailed!).
Pulse

108mm secret nailed.....my memory of the Australian standards restrict secret nailing to around 80mm boards.

Edit...... Australian Standard states maximum width is 85mm

Kev M

[Larry McCully]

Listen to trevor , his advise is spot on in this instance. Now to further your solution to this hic up. Yo need to go under the house and apply a down ward force to the risen area. You need to use something that will pull the joist back down to the bearers. get yourself some builders galv strap. multinail one end on to the joist at short intervals apart, then as you pull the joist down and at the point that the joist touches the bearers again have someone nail the other end of the strap onto the bearer. All you are doing is fastening the joist back down to the bearer. over a period of time the timber will relax and settle, then access the expansion rate as per trevors advise. You may need to either replace the floor or install a new one over the top of the old one. But is the worst case sinerio. You will experence a perminate gapping. What has happened is that with the expansion of the saturated boards, two things have happened. 1/ The expansion has draged out the secret nails and with the shrinkage over the next couple of weeks, the nails stay in that position and wont return with the shrinkage, so the floor will be loose and not have a tight fit.
2/ timber floors will to a point shrink back, however you will not recieve a 100% return, the fibre in the grain distorts.
Now you can sand out the cupping, but you will need to make 100% sure that all framing components are back to emc or otherwise if you get a sander to flatten out the floor before emc then when the boards do shrink back, you will get a reverse cupping. I have had huge experence in wet weather installation and every time this type of damage is incurred, the only result is to replace the floor. If you try to do a patch up, it never works succesfully. The builder has a responsibality to ensure that the newly laid floor is protected from all and every element that will cause a damage. I support you in your troubles and hope the best for you and the out come. It is fixable, and with the correct procedure you will have victory. You need to speak to trevor (clock40)personaly about this. he is a master at this sort of situation. If i can be of service to you as well do not hesitate it calling out.

[Larry McCully]

You need to install sub floor vents, it is a must.
www.hyne.com.au/downloads/dih_downloads/timbertds/14_ventilation.pdf (http://www.hyne.com.au/downloads/dih_downloads/timbertds/14_ventilation.pdf)

find the one suitable to you and install.

[Gaza]

Bugger.........

I knew there was a reason we walk off jobs if;
A. The windows are not in.
B. The wet trades are not done.
C. The builder/designer/owner wants to secrete nail a floor over 85mm.

Ring the floor company up get them to get there butts there to fix it. The AS stats that the site must be inspected before work starts. The conditions described fall out side the AS.

In my opinion rip the thing out and redo it, its never going to be 100% and your brother will look at it every day and feel like crap. For a few thousands problem done fix, solved.

[Larry McCully]

it is posible to secret nail, but it is recomended to top nail as well

[Larry McCully]

Bugger.........

I knew there was a reason we walk off jobs if;
A. The windows are not in.
B. The wet trades are not done.
C. The builder/designer/owner wants to secrete nail a floor over 85mm.

Ring the floor company up get them to get there butts there to fix it. The AS stats that the site must be inspected before work starts. The conditions described fall out side the AS.

In my opinion rip the thing out and redo it, its never going to be 100% and your brother will look at it every day and feel like crap. For a few thousands problem done fix, solved.

[ptyltd]

I'm going to jump in here with a question if I can folks. I have just put down 50m2 of Ironbark 19mm T&G straight onto joists. Clearance to ground is at least 400mm to the bottom of the bearer so probably about 600mm to the bottom of the floor. The 3 sides of the extension are all open so should be plenty of ventilation to the subfloor area. If I get a bit of water runoff going under the house (which might take a few days to dry off) is this going to present similar problems with my T&G?

The reason I ask is the existing place used to get a fair bit of water running under the house with big rains and the old T&G seem fine for it. Whilst I have done some temp stormwater measures I wasn't going to do them proper till a bit later (in hindsight I should have done them prior to the subfloor being built but as I wanted to incorporate bloocks etc. around the perimiter - there is a slight site cut - I was leaving this till last) thus some water will occasionly run under the house over the new T&G floors. I guess I am asking is it OK to leave like this for a few months?

[echnidna]

It should be ok.
Pity you hadn't spread a truckload or two of packing sand around before you fitted the floor.

[glock40sw]

I'm going to jump in here with a question if I can folks. I have just put down 50m2 of Ironbark 19mm T&G straight onto joists. Clearance to ground is at least 400mm to the bottom of the bearer so probably about 600mm to the bottom of the floor. The 3 sides of the extension are all open so should be plenty of ventilation to the subfloor area. If I get a bit of water runoff going under the house (which might take a few days to dry off) is this going to present similar problems with my T&G?

The reason I ask is the existing place used to get a fair bit of water running under the house with big rains and the old T&G seem fine for it. Whilst I have done some temp stormwater measures I wasn't going to do them proper till a bit later (in hindsight I should have done them prior to the subfloor being built but as I wanted to incorporate bloocks etc. around the perimiter - there is a slight site cut - I was leaving this till last) thus some water will occasionly run under the house over the new T&G floors. I guess I am asking is it OK to leave like this for a few months?

G'day.
I'd be inclined to cut a temporary spoon drain around the perimiter to minimise the under floor moisture ingress. After all, it's better to do it now than have the floor fail later on.

[Larry McCully]

Because you have 3 sides that are open, you will have enough subfloor ventilation to carry of any relative humidity out. However it would be safe to astrevor sugested to dig a spoon drain around the house to redirect any ponding away from the cavity.