How much maintenance do latest standard plaster houses need?

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Batman

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# 254391 10-Aug-2019 10:32

I see a lot of houses using something called stotherm plaster system where cement 50mm boards are installed onto the frame and then plaster boards over the cement board.(or are they prestuck together from factory??)

These are 2010+ houses.

I understand the cladding is required to last 15 years yes.

But if anyone has done any research into these kind of houses that could shed light on how good or how bad there are, I'm all ears.

Please and thank you.

Involuntary autocorrect in operation on mobile device. Apologies in advance.

Disrespective

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# 2294889 12-Aug-2019 16:27

Sto are a pretty well known brand in the NZ building industry. Their reps do the rounds and I have used their products on a number of projects over the years and would without hesitation propose their systems again. They've always been easy to deal with and more than accommodating when things crop up on site.

That said I have't specified the stotherm system myself (colleages have) nor have I been able to see something get to the end of it's 15 year warranty (the oldest project I've specified it on is probably about 8 years old).

So long as you maintain it to the requirements Sto set out then there shouldn't be a problem (famous last words riiight)

Section 5 of the specification I have on file for the system states:

5. MAINTENANCE
Refer; Sto Maintenance Schedule for comprehensive guide.

The StoTherm Masonry Insulation System must be cleaned annually by low pressure washing to remove all existing surface contaminants with special attention to non-rain washed areas. When recoating is required at the 7/8-year period to maintain long-term integrity and a pristine condition this can be carried out using a Sto façade paint or sealer over a cleaned surface. Where a colour change is required, Stoanz Limited should be consulted for a specific specification.
Annual inspections are to be implemented after completion to clearly identify any faults in the cladding, sealant beads, flashings and any other connections. A repair process must be implemented immediately to address any faults so the long-term warranty is not compromised.

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# 2294977 12-Aug-2019 18:03

Wow sounds like a lot more work than a brick clad house thanks

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# 2294984 12-Aug-2019 18:20

So I'm thinking in terms of maintenance of cladding it's
Brick < timber < plaster?

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timmmay

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# 2295101 12-Aug-2019 20:09

Weatherboard takes maintenance. You have to check at least annually for gaps between weatherboards, horizontally and vertically, bubbles in the paint, any gaps or leaks really. They will probably need to be repainted after about ten years, hopefully just a sand and top coat but maybe a full strip if the first paint wasn't done well or it's an oily wood.

I'd done with wooden doors and windows as well - PVC all the way. I wish the whole house was made of PVC.

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# 2296437 13-Aug-2019 11:32

In addition to the material you also need to consider the final coating. Resene have a maintenance schedule you should adhere to if using their products. Other paint/coating suppliers have similar.

https://www.resene.co.nz/comn/services/maintenance.htm

Generally speaking I suppose you're right that bricks require the least maintenance, but it still isn't nil. See: https://www.maintainingmyhome.org.nz/issues-and-repairs/IssueSearchForm/?terms=230,356

There are also other claddings to consider, including long run steel, cementitious sheets, cedar vs pine weatherboards, etc. And each type of cladding also has different longevity e.g. Colorsteel Endura vs Maxx.

While the house I own at the moment is brick clad, if I was living in Wellington, or anywhere more likely to be seismically active, then I would much prefer a timber weatherboard cladding as it is much more forgiving to movement.

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# 2297817 14-Aug-2019 09:01

Disrespective:

Sto are a pretty well known brand in the NZ building industry. Their reps do the rounds and I have used their products on a number of projects over the years and would without hesitation propose their systems again. They've always been easy to deal with and more than accommodating when things crop up on site.

That said I have't specified the stotherm system myself (colleages have) nor have I been able to see something get to the end of it's 15 year warranty (the oldest project I've specified it on is probably about 8 years old).

So long as you maintain it to the requirements Sto set out then there shouldn't be a problem (famous last words riiight)

Section 5 of the specification I have on file for the system states:

5. MAINTENANCE
Refer; Sto Maintenance Schedule for comprehensive guide.

The StoTherm Masonry Insulation System must be cleaned annually by low pressure washing to remove all existing surface contaminants with special attention to non-rain washed areas. When recoating is required at the 7/8-year period to maintain long-term integrity and a pristine condition this can be carried out using a Sto façade paint or sealer over a cleaned surface. Where a colour change is required, Stoanz Limited should be consulted for a specific specification.
Annual inspections are to be implemented after completion to clearly identify any faults in the cladding, sealant beads, flashings and any other connections. A repair process must be implemented immediately to address any faults so the long-term warranty is not compromised.

Hi forgot to thank you for your post. So it needs to be repainted every 8 years?

Involuntary autocorrect in operation on mobile device. Apologies in advance.

Batman

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# 2297818 14-Aug-2019 09:05

timmmay:

Weatherboard takes maintenance. You have to check at least annually for gaps between weatherboards, horizontally and vertically, bubbles in the paint, any gaps or leaks really. They will probably need to be repainted after about ten years, hopefully just a sand and top coat but maybe a full strip if the first paint wasn't done well or it's an oily wood.

I'd done with wooden doors and windows as well - PVC all the way. I wish the whole house was made of PVC.

ok thanks! very handy to know!

Involuntary autocorrect in operation on mobile device. Apologies in advance.

Fred99

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# 2299116 14-Aug-2019 12:08

I'd much rather do a washdown and roll a couple of coats of acrylic paint on a flat/textured plaster surface than repaint weatherboards. When I reclad our place when the bricks failed due to quakes (so much for the "permanent material" theory in NZ), I used quite a lot of linea weatherboard, which seems to be much less of a maintenance nightmare than wooden boards. Even when brand new and not needing extensive surface prep, painting it was a slow tedious process.

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# 2299261 14-Aug-2019 14:44

Batman:

Hi forgot to thank you for your post. So it needs to be repainted every 8 years?

Essentially, yeah, if you want to keep the warranty valid. And if you repaint it a different colour, you need to make sure it's reflectance value is suitable so as to not increase thermal expansion and contraction. e.g Don't paint it black or you risk the surface cracking.

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# 2299278 14-Aug-2019 14:59

Disrespective:

Don't paint it black or you risk the surface cracking.

Everything seems to be painted black these days, as it is seen as the trendy colour. I saw a new plywood and batten board clad house where the expansion and contraction had liked to unpainted white gaps showing in the corners and edges.

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# 2299333 14-Aug-2019 15:47

Hi can I also ask - saw a house built and consented in 2005 under the new building code.

It is has a cavity with 25mm batten, and is clad with hardibacker over chicken wire.

What do you make of that? can you still build it like that under the current code?

eg if the cladding is damaged, i presume it costs quite a bit to repair?

Involuntary autocorrect in operation on mobile device. Apologies in advance.

Disrespective

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# 2299352 14-Aug-2019 16:27

mattwnz:

Everything seems to be painted black these days, as it is seen as the trendy colour. I saw a new plywood and batten board clad house where the expansion and contraction had liked to unpainted white gaps showing in the corners and edges.

Yeah and some substrates are better than others but, as an example, every fibre cement sheet cladding system (irrespective of manufacturer) are not going to warranty it if your LRV (light reflectance value) doesn't meet their requirements. It's a fact that not everyone, as evidenced by the number of dark painted houses, understands.

I'm not sure if plywood has a similar limitation to be honest. I'd guess not as it's more capable of managing movement without catastrophic failure.

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# 2299357 14-Aug-2019 16:37

Batman:

Hi can I also ask - saw a house built and consented in 2005 under the new building code.

It is has a cavity with 25mm batten, and is clad with hardibacker over chicken wire.

What do you make of that? can you still build it like that under the current code?

eg if the cladding is damaged, i presume it costs quite a bit to repair?

Cavities are good but Hardibacker is an internal substrate lining I think now. I guess it may have been externally fixed under a different name a decade ago. The chicken wire *should* be behind the cavity and holding a building paper onto the studs, if anywhere, but isn't part of the modern building code.

Essentially, if the cladding failed and you had a cavity then it would be much less likely to have caused damage to the structure, which consequently should be cheaper to repair. The whole point of the cavity is to aid in the drying of the cladding after it has deflected the rain, but also helps keep moisture away from the structure.

If I could choose between two houses with the same cladding, one with a cavity and one without, i'd pick the cavity construction 100% of the time.