Stucco cladding on 80's house

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mattwnz

20147 posts

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#126898 23-Jul-2013 13:35

I have a family member looking at buying an old 80's house. It looks really nice, but it has old style stucco cladding, and have been told it has been reroofed twice. It also has that old black plastic piping which is known to leak. My main concern for them is the stucco walls. It is not on a cavity, so is direct fixed to the studs. The stucco is thick, and appears to be traditional cement over wiremesh, over a plywood substrate. But you can see hairline cracks in the joins and it all appears to have been painted or recoated quite recently. It also goes all the way to the ground, so could be sucking up moisture. My concern is the condition of the timber studs under it, as it is an unknown. The roof has no overhangs, although it is a pitched roof. The building report done on it hasn't picked up many problems, apart from identifying these things, and identifying old water staining on the ceilings and walls. But they haven't picked up any dampness. Just wondering what peoples thoughts are. As it is such a big investment, personally I think they need to get a destructive building inspection done, to open up the walls to see the condition, to check that there isn't any rot and mould growth. But that is very costly, and it is a tender, and I don't think the owners would agree to that sort of thing.

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Smpl Mnmlst
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#864268 23-Jul-2013 13:54

It's not clear whether the Building Report was commissioned by your family member (and is addressed to them) or if it was done for the vendor? If the latter, your family member should consider getting their own report done, including moisture testing.

Sometimes I just sit and think. Other times I just sit.

gazbo

89 posts

Master Geek

#864275 23-Jul-2013 14:14

Direct fixed stucco is no longer permitted for a reason. It has the highest risk of leaking of all common cladding types. If the cladding is in contact with the ground then the building is not compliant with the building code (even though it was built prior to the existence of the code ie 1991 - cladding in contact with the ground was not permitted as far back as the 60s with the earliest editions of NZS3604 and model bylaw NZS1900). If you had to repair it a total reclad would be the worst case and unfortunately likely scenario.

mattwnz

20147 posts

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#864281 23-Jul-2013 14:24

eracode: It's not clear whether the Building Report was commissioned by your family member (and is addressed to them) or if it was done for the vendor? If the latter, your family member should consider getting their own report done, including moisture testing.

It was a vendor commissioned report. It did have mositure testing, but it didn't appear to have the type that you drill a hole and insert the probes. It appears from the photos it was just touching the surfaces. If they did go ahead, I think they would have to make a destructive building report a condition. The thing is the house looks like it has been done up to sell on the outside, new roof, new paint and plaster on cladding. The windows are also recessed, but their is no sill flashing, just a plaster sill, which I think is also a requirement with stucco cladding over a timber frame, although not picked up in the report.

mattwnz

20147 posts

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#864287 23-Jul-2013 14:30

gazbo: Direct fixed stucco is no longer permitted for a reason. It has the highest risk of leaking of all common cladding types. If the cladding is in contact with the ground then the building is not compliant with the building code (even though it was built prior to the existence of the code ie 1991 - cladding in contact with the ground was not permitted as far back as the 60s with the earliest editions of NZS3604 and model bylaw NZS1900). If you had to repair it a total reclad would be the worst case and unfortunately likely scenario.

A reclad is possibily the better scenerio, replacing the framing underneath if it is rotten or mouldy would be far worse. Also it would have to be replaced with a system on a cavity which would increase it's thickness, and as the roof doesn't have overhang, it would mean the roof would need a lot of work too. I think the plastering to the ground is more recent, when it was last done up so don't think it was always like that. It is only like that in certain places, such as tiled entrances and on upstairs windows where the bottom of the cladding almost comes into contact with the roof. I think there has to be a 35mm minimum gap there under current building code.
The problem I saw when I first viewed the property, is that you can see the plywood sheet lines under the stucco, which could suggest that the edges have swelled.

gazbo

89 posts

Master Geek

#864301 23-Jul-2013 14:43

The building code does not prescribe solutions such as the 35mm gap you're talking about. The acceptable solution E2/AS1 does but it is not the only solution. Sill flashings may be buried under the plaster. Framing replacement is a standard part of re-cladding.

graemeh

2078 posts

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#864303 23-Jul-2013 14:46

While you are doing the reclad you also need to replace that black plastic pipe as it is a leak waiting to happen.

We had that pipe and in recent years the pipes themselves started failing. Prior to that it was the joints that failed.

mattwnz

20147 posts

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#864312 23-Jul-2013 14:53

gazbo: The building code does not prescribe solutions such as the 35mm gap you're talking about. The acceptable solution E2/AS1 does but it is not the only solution. Sill flashings may be buried under the plaster. Framing replacement is a standard part of re-cladding.

From what I can see, the building code E2 does state that the minimum gap must be 35mm for all claddings on a roof. Otherwise any other system would need to gain consent as being an acceptable solution. Personally I would want more than 35 mm. Sure, sill flashings maybe under the plaster, although impossible to tell, and from I can see, these days they are best to lap over the top of the cladding as per the acceptable solution in the building code.
I don't think framing replacement is a normal part of cladding replacement. As soon as you replace the framing, you are talking about replacing the internal linings to, as well as all services in that wall, floor surfaces adjoining it, essentially a rebuild of that part of the house. I have reclad a weatherboard house before, and that only involved replacing the weatherboards and putting in new building wrap.

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wellygary

8315 posts

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#864328 23-Jul-2013 15:18

Just note that NZS 3602 which allowed kiln dried (untreated) timber framing did not come into effect until 1995-ish, so even if the house you talked about is leaking, it is likely that the framing is in a much better state than you might think,

mattwnz

20147 posts

Uber Geek

#864334 23-Jul-2013 15:23

wellygary:
Just note that NZS 3602 which allowed kiln dried (untreated) timber framing did not come into effect until 1995-ish, so even if the house you talked about is leaking, it is likely that the framing is in a much better state than you might think,

You are right, and did consider that. But any dampness to framing over a long period isn't good, and it will likely still only have minimum treatment for borer, possibly h1. They have to look at what they plan to do long term with the cladding, or just leave it as it is and live with it. Just that I think it will affect the value of the house and the number of people who would buy it in the future.

mattwnz

20147 posts

Uber Geek

#864338 23-Jul-2013 15:25

graemeh: While you are doing the reclad you also need to replace that black plastic pipe as it is a leak waiting to happen.

We had that pipe and in recent years the pipes themselves started failing. Prior to that it was the joints that failed.

Yes, it is NZs silent leaking problem, no one really talks about it. The house I live in now has it, although most of it has been replaced. Often it can be replaced by removing parts of the gib, so usually best done from the inside.

gazbo

89 posts

Master Geek

#864342 23-Jul-2013 15:28

You are confusing the acceptable solution E2/AS1 with the building code clause E2. Anything different to E2/AS1 is an alternative solution which each certifier decides for themselves during consent.

35mm was chosen as the smallest gap still large enough to stop people filling it with sealant. As long as the surfaces are at least 6mm apart then capillary uplift of moisture from the lower surface is not possible.

These days a reclad is associated with leaky buildings and timber replacement and internal lining replacement, plumbing and electrical work is normal. It is highly unlikely that framing replacement would not be required in the situation you describe.

You are quite correct not to trust hidden flashings in this scenario. EIFS systems use them successfully currently but they are on a drained and vented cavity system and have been well tested (some of them).

gazbo

89 posts

Master Geek

#864371 23-Jul-2013 15:52

"The problem I saw when I first viewed the property, is that you can see the plywood sheet lines under the stucco, which could suggest that the edges have swelled."

This is the salient issue. Moisture has likely swollen the framing at the ply sheet edges. H1 boron treated framing does have good decay resistance but is only a delaying factor. It may give 5 - 10 extra years over untreated framing before decay affects the framing to the point it needs replacement. We are now at 25+ years?

I'd advise them to either walk away or allow an appropriate price reduction to account for the worst case scenario in their offer.

pctek

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#864804 24-Jul-2013 08:35

It also has that old black plastic piping which is known to leak. My main concern for them is the stucco walls.

Really? I'd be concerned about the plumbing. Run away now. It's BAD, BAD, BAD.
You'd have to rip the whole lot out and replace it all.
Major.

Never mind issues with leaking cladding.....

Fred99

13684 posts

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#864808 24-Jul-2013 08:44

It's a bit of a major doing a re-clad with a different / altered system from original. I'm doing this at the moment as part of earthquake repairs to our house built in 1962. (in our case cash-settled from EQC/Insurer and "self-managed repair) Building consent is mandatory. Design costs and consent fees add quite a few thousand $$$ to the job. It's important that details are considered thoroughly - adding a cavity alters reveals around windows/doors, and how cladding lines up with foundations etc. The original joinery may not work easily with flashing systems for the new cladding. With an older house like ours, it's also an opportunity to add insulation to the exterior walls - also in our case we're also adding extra bracing to all framing. With designer, builder, cladding specialist, scaffolder in our case, but possibly other sub-trades needed - it's a potential can of worms.
I wouldn't buy a house which possibly needed a full re-clad, without thorough investigation of the scale of the whole job. Don't assume that the job would be straight-forward. A new cladding system cost might range from $80-$180 / m2 as a base price, but unless the job was a simple "like for like" replacement, the cladding material installation itself may be only a fraction of the total costs.

tdgeek

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#864821 24-Jul-2013 08:53

Back in the day stucco was a good cover up for less than ideal weatherboards. Not saying your example is dodgy, but could be.

Recladding is a great option as that does much more than taking away the doubtful stucco or the doubtful or possible issues.

1. Add batts into the walls.
2. Update/add any wiring as that has much easier access in exterior walls
3. Plumbing that goes through exterior walls can be attended to
2. Building paper is added
3. New cladding is new, looks great.

The benefit, assuming the sale price reflects concerns over what unknowns are actually bought, is that the health and financial status of the building is known. Great for the new occupier, and when they sell.

I'd get a ballpark quote and take it from there.

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