Wood Knowledge: Working With Wood And Water

May 14, 2024 | wood knowledge

Do you worry about how to manage your wood once it’s delivered to site?

We hear lots of questions and concerns about how to manage timber once it gets to site, especially with the change in climate and the frequency and volume of rain we seem to have have these days.

We thought it might be useful if we shared some of what we know.

Here are our 8 top tips for taking care of wood in the wet;

1.Lift it up

For so, so many reasons, please don’t leave your timber sitting on the ground (or floor). Use some wooden bearers (sacrificial timbers of the same section size to create a level – we use douglas fir 100×100’s) to lift it up, away from direct contact with the ground and any potential standing water.

2.Let it breathe

By all means, cover up any wood you are storing externally to shield it against the elements, by try not to seal it.

Wet wood needs to be able to evaporate moisture at all times. Both wet and air dried wood need to be ventilated. Two pieces of wood together create a lovely, warm insulated microclimate where bacteria and moulds can thrive. Ventilate to prevent that happening. If you do need to store wood for long periods of time outdoors you might want to invest in netting for covers and sticks (we’d advise using Poplar) for creating airflow.

3.Low down detail

Whether it’s cladding, fencing or posts, any external, vertical timber surface will be vulnerable at ground level from water splash back when it rains. Good practice would be to either start wood surfaces at 300mm above ground level or factor in easy maintenance or replacement of low level timbers. Padstones, or staddlestones are a traditional, elegant way to do this for stand alone posts of timber frames.

4.Leaching allowed

It’s one of the brutal truths about working with Oak outdoors woodfolks; the tannins will leach.

And it may well stain whatever is underneath it. Temporarily. If you just can’t get comfortable with the rusty tea-stains and the tannin reality then there are ways to work with it.

Such as… scheduling exposed wood surfaces for autumn installation. This gives them 3 lovely long wet seasons to get rained on and thoroughly washed and seasoned before the summer heat and UV show up. It sounds dramatic but you could also delay finishing the strip of ground beneath your wood for a year or so until the tannin has washed through and your beautiful paving will be stain free. Read our Tannin blog for a bit more info.

 

5.Luscious metals

The only sure way to prevent corrosion and discolouration or to ensure strength and longevity is to use austenitic stainless steel (316 grade) fixings, in whatever form you need them.

Most timber guidance* offers a range of metals but they’re not created equal! The austenitics aren’t as easy to come by and they cost more that the other options but you’ll be so glad (and maybe even a little smug) when you look at your fixings in 10 or 20 years time and they still look like new.

 

6.Longevity designed in

Don’t skimp on the detailing. It doesn’t matter whether it’s cladding, framing or fencing, the design details and how well the wood is fixed and fitted, will be the difference in the service life of your wood. Intelligent detailing can make the lowliest of timber species last centuries, regardless what the Durability class it is.

 

7.Less is more

Time. The way timber supply chains operate these days there is no need for you to have your timber sitting on site any longer than necessary. Yes, it’s best to acclimatise for indoor use but for outdoors, the less time it sits there waiting to be used the better. Unless it’s stored really, really carefully wood that sits around on site goes out of shape, gets damaged, degraded, changes moisture content, and isn’t serving any purpose other than getting in the way. Tell your timber supplier when you actually need it, they’ll manage the production to deliver just in time.

 

8.Last word

Wood that’s been rained on is not wet. it’s moisture content will not change overnight. On the surface, yes, it may get wet, but it’ll dry off as soon as the rain stops (as long as it does!). Wood of every species, takes weeks, if not months, to give off, or take on just 1% of moisture. the drier it is, the longer this process will take. So fret not woodfans. if it started hammering down when you had your new fave KD waney edge board on the roofracks it’ll be fine. And if it’s beams or cladding you really don’t need to worry. That’s what seasoning is all about.

 

If you find you still have questions, concerns, worries about your wood and how to look after it outdoors, don’t let it give you sleepless nights. Get in touch. Tell us your woes and we’ll see if we can help ease them. Call 01730 816941 to speak to us on any given weekday or email us.

MORE INFO

*Timber Guidance:
TRADA Moisture in Wood pdf
TTF Cladding Handbook pdf

Read the Tannin blog

Get Moisture Movement data
Get Species data
Get Durability data