Dean Carpenter

Problems with hotwood cladding

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17 hours ago, PeterStarck said:

@Dean Carpenter How thick is the cladding? I do not understand how the vertical battens are having the effect of altering the colour of the cladding. I clad our house in Western Red Cedar 'no.2 clear and better' grade and had the profile I wanted, which was 15mm thick, machined for me. The cost of the cladding was under £40/m2. Nowhere are the battens visible. We haven't treated the cedar and it's been up over four years and the colour variation is significant over the whole house. The rain affects the cladding by washing out the colour and it turns grey quickly in those areas but where it's protected it's still brown.

 

 

That mirrors my experience with untreated larch.  There is a great deal of colour variation still, after three years, with the sheltered areas under the eaves still looking quite reddish/brown and the exposed areas (especially the East elevation, which gets most of the early morning sun) having been the quickest to turn grey.  On the South elevation there is a lot of variation, the full spectrum of different colours really, although it is very gradually all toning down to around the same grey colour, it just takes a long time.

 

Water staining is a problem.  We fitted standard gutters and they are not up to taking the flow from the 45 deg pitch roof that is mainly covered with solar panels, as the water runs off to fast in very heavy rain.  the result is that they overflow and there are clear stains in the cladding where this has happened.  I'm fitting deep flow gutters, but wish I'd done it earlier before the staining occurred.  My hope is that it will fade out with time.

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The image shows the west elevation but the worst is the south elevation (to the right of the image). It's a problem 360 deg around the house. see below image of south elevation. This was taken a while ago. It's now a whole load worse

 

 

20171012_073213.jpg

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here's a close-up image, which indicates to me the problem is specific to the board as you can clearly see one board worse than the other

close-up-smaller.jpg

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That's a black surface mould, that's very common and more often found on stored timber ordecking.  As there is no antifungal treatment applied, and the thermal treatment process has no effect at all on the surface resistance to mould growth like this, then this is exactly what I'd expect to see on a timber like ash that has no natural antifungal resins etc that would tend to prevent it.

 

The mould not going cause rot in the timber, but will stay on the surface, because the thermal treatment makes the internal structure of the timber resistant to the growth of mould beyond the surface.  It will tend to proliferate on any surface that stays slightly wetter, or cooler, than any another, and the change in grain structure between adjacent panels will be more than enough to cause the surface moisture or temperature difference needed in order to cause the effect you're seeing.  The black mould species is probably very similar to the types found growing on cool, damp, bathroom surfaces, and the patterning where the battens are is most probably due to slight surface temperature variations in those areas

 

It should wash off fairly easily, but may leave some staining, and will be a recurring problem, as thermally treated non-durable timber has no inherent resistance to surface mould growth at all, it needs some form of surface treatment to prevent this.

 

I think you may have been mislead as to the properties of this material, most probably by a sales person.  There's nothing that I can find anywhere in the company literature that suggests there is any resistance to surface mould growth, but there do briefly mention that customers may wish to consider some form of surface treatment or stain, which sort of skates around the problem that they know that surface mould may be an issue in some climates.

 

Ash is a non-durable timber, with virtually no inherent resistance to rot.  In it's untreated form it's durability rating is 5, as poor as you can get, about the same as balsa wood;  many softwoods are a great deal more durable.  The thermal treatment improves the durability rating to 1, but has no effect at all on the surface properties.  There are no resins or mould-resistant compounds within ash, so even thermally treated it is still going to attract surface mould growth, much the same as the way softwood decking does.

 

You can try and fight the supplier, and the advice that @Ferdinand has given is about as good as any I can think of, or you can clean the surface up and treat it with something like Sioox, as already suggested.  My personal opinion is that you've been misled as to the difference between durability and surface appearance, but proving that could be a significant challenge.

 

 

Edited by JSHarris
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One thing I did not mention was engaging Trading Standards, but I know nothing about their remit across the EU. You need to talk to them.

 

Whatever you are going to do, I think I would want it finished significantly before Brexit - may cause more complications even if only a bigger library of potential excuses / opportunity for smoke screens.

 

Could it be as simple as an expert report, and a County Court action against the UK supplier for the cost of Sioo + putting it on to do a fix or alternatively for replacement (which sounds too big for the Small Claims track)?

 

Ferdinand

 

Edited by Ferdinand

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Your best bet would be to do as above and try and use social media to more or less embarrass them into helping you out. The various Twitter pages that contain pics of new builds that have turned out to be a disaster definitely work. 

If this method is unsuccessful and you don't want to open the massive can of worms that a court case might entail then it's going to be up to you to come up with a make do remedy. Wash it down and treat it for mould resistance and then use one of the paint/stain type products mentioned above to hopefully get you near enough the consistent colour you want. 

You clearly have been misled so aleast by posting here anyone doing a Google search should be alerted to this post and should hopefully reconsider buying from them.

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Reading around the competitor "thermo" timber sites and they also to specify "European redwood & whitewood". Stuff like Silver fir, Norway spruce etc. 

 

Weird how the mould build up is more on the South, is it because it gets more Sun for growth?

 

Maybe jet wash then anti fungal and a clear treatment? My only worry is that might arrest the patchiness and leave it looking as is. Guessing a stain is in order. Doing a test area first is essential I reckon.

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2 hours ago, Ferdinand said:

One thing I did not mention was engaging Trading Standards, but I know nothing about their remit across the EU. You need to talk to them.

 

Recently I tried to speak with Trading Standards about a UK consumer issue and they referred me to CAB because they don't deal with domestic consumer problems any longer. Apparently they are only interested in commercial trading issues such as fake goods and dangerous toys.

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5 minutes ago, PeterStarck said:

Recently I tried to speak with Trading Standards about a UK consumer issue and they referred me to CAB because they don't deal with domestic consumer problems any longer. Apparently they are only interested in commercial trading issues such as fake goods and dangerous toys.

 

That is actually different to what CAB seem to say.

 

https://www.citizensadvice.org.uk/consumer/get-more-help/report-to-trading-standards/

 

I agree though .. getting to Trading Standards can be a wild goose chase.

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Mirrors my experience with Trading Standards.  I tried hard to engage them over the import of Chinese battery chargers that were being sold via a well-known auction site, from a "seller" in Southampton.  These were bloody lethal, with the line and neutral crossed on the unit I bought, no earth protection, no double insulated either and with a 50/50 chance that the negative battery charge lead could be at mains potential (mine was).  They weren't interested at all with dealing with a consumer complaint. 

 

One reason was that the "seller" in Southampton was just a drop-shipping warehouse, and the seller was really in China.  This is extremely common, apparently, and the give away is when you see an apparently UK-based transaction being handled during Chinese business hours - it means the seller is not in the UK as claimed, and just has the goods in a UK warehouse for faster shipping.  What's worse is that you have no come back at all under consumer law, as although it seems on the surface that you've bought goods from a UK seller, so the UK sales of goods and services regulations should apply, in reality you've been conned and have purchased direct from China......................

Edited by JSHarris

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My experience with the ukecc was very positive. They dealt with their German counterparts after a faulty item that the German supplier refused to deal with. From a refusal came an offer of a repair which I rejected and eventually came a full refund.

 

It all took many months.

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Any chance of claiming this back via your credit card, if you used it to do the purchase.

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1 hour ago, JSHarris said:

Mirrors my experience with Trading Standards.  I tried hard to engage them over the import of Chinese battery chargers that were being sold via a well-known auction site, from a "seller" in Southampton.  These were bloody lethal, with the line and neutral crossed on the unit I bought, no earth protection, no double insulated either and with a 50/50 chance that the negative battery charge lead could be at mains potential (mine was).  They weren't interested at all with dealing with a consumer complaint. 

 

One reason was that the "seller" in Southampton was just a drop-shipping warehouse, and the seller was really in China.  This is extremely common, apparently, and the give away is when you see an apparently UK-based transaction being handled during Chinese business hours - it means the seller is not in the UK as claimed, and just has the goods in a UK warehouse for faster shipping.  What's worse is that you have no come back at all under consumer law, as although it seems on the surface that you've bought goods from a UK seller, so the UK sales of goods and services regulations should apply, in reality you've been conned and have purchased direct from China......................

 

We are drifting but HMRC for VAT avoidance might get those, since HMRC are now on that one after a campaign essentially by one man.

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7 minutes ago, SteamyTea said:

Any chance of claiming this back via your credit card, if you used it to do the purchase.

 

Very good point.

 

Probably even better if you paid via an Amex run Amex card, as they fight your corner well.

 

Aha. Section 75 has a 30k ceiling, with a couple of exceptions.

https://www.moneysavingexpert.com/shopping/section75-protect-your-purchases#when

 

How did you pay?

 

You need more detailed advice than Is within my experience on this front, but certain bank accounts have protection policies now. 

Edited by Ferdinand

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8 hours ago, Dean Carpenter said:

The image shows the west elevation but the worst is the south elevation (to the right of the image). It's a problem 360 deg around the house. see below image of south elevation. This was taken a while ago. It's now a whole load worse

 

 

20171012_073213.jpg

 

8 hours ago, Dean Carpenter said:

here's a close-up image, which indicates to me the problem is specific to the board as you can clearly see one board worse than the other

close-up-smaller.jpg

 

How long has the cladding been up? We have larch cladding on part of our house, which has been up for over 12 months, and that is still in the process of transitioning from fresh to weathered. At times it hasn't looked great, but that was early on in the process.  

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Do you have any cladding left over? Maybe you could knock up a "test rig" with a few boards and see how it performs after staining or whatever for a couple of months.

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Was there perhaps something wrong with the way batches were randomised on site, or differences between batches?

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10 hours ago, Ferdinand said:

Was there perhaps something wrong with the way batches were randomised on site, or differences between batches?

 

I doubt it.  It's pretty much exactly how non-durable timber with no surface treatment will behave when it gets cool and damp.

 

The problem is that the company failed to highlight that surface treatment would be needed in order to maintain an even looking appearance and only stressed the long term durability.  It's undoubtedly durable, but unless regularly cleaned or surface treated it's always going to attract sporadic black mould growth, as nothing has been done to the timber to make it have any surface anti-mould properties at all.

Edited by JSHarris
typos

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Hi to all: unfortunately it was paid by bank transfer. I do have some left over that I kept for repairs as/when needed. It's been up for about 1.5 years. 

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I thought I'd update this thread: Cleaning with a water, light detergent and a brush not only took forever but it was pretty patchy too. Like painting the Golden gate Bridge - before I finished the bit I had started had already deteriorated.  I didn't want to jet-wash as I was advised against it as it would apparently roughen the surface and further help the dreaded mould to grow even more. 

 

After talking to a few providers of commercial cleaning products that would have cost me many hundreds of pounds to buy let alone the labour to apply, one of the technical people was very honest with me and recommended I try soaking the surface with clean water then using a weak bleach/water mixture 1/10 applied with a fine spray nozzle. 

 

At first this looked promising but the mix was drying-out before it had time to work properly. I increased the mixture incrementally to about 1/4 and this worked really well. IMPORTANT to do this at a time of the year when it's still quite damp outside  and cloudy i.e. so that the mixture will not evaporate too fast thereby giving it time to work. 

 

It's very important to thoroughly soak the surface with clean water, starting high up and I did arreas about 3m2 at a time. I applied the mixture to a really wet surface so that on contact the mould can run down easier.  Leave it for about 20 mins max then wash with clean water. After looping the whole house  once some stains were apparent where the mould had run. A second application of the whole house cleaned that up. 

 

After about 2 weeks the cladding had turned to near white, like drift-wood. At first I was worried but since I did this very early spring it's now weathered back to a kind of grey.

 

I wanted to leave it for 1 summer and 1 winter to see what happened 

 

There are no apparent signs that the bleaching has damaged the wood

 

The surface is a kind of grey but not grey enough for my liking

 

Right now the mould is showing  signs of coming back but nothing like the images above

 

My next step is to repeat the cleaning process in a few weeks time but this time it should be easier as the cladding is nowhere near as bad as it was. In the summer I'm going to  treat it with Textrol. This was apparently used on the London Velodrome so if it's good enough for them it should be good enough for me. Not cheap though at  approx £1,500 materials only for my job 

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Got a photo? 
 

still not interested in black barn paint and be done

with it?

Edited by gc100
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Our Thermowood cladding has been up for about 3 years or so now. Unlike yours @Dean Carpenter ours is heat treated Redwood. We chose to coat it with a clear UV varnish as we preferred to maintain the wood colour rather than let it go grey. Apart from some slight fading on the south elevation it looks much the same as the day it was put up. We have sections on all elevations, and have no sign of any surface growth anywhere. Whether the varnish has helped or not I couldn't say, but for anyone considering Thermowood as opposed to Hotwood then hopefully our experience will provide some assurance.

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