Shed timber treatment and paint

TimW snipped-for-privacy@nomailta.co.uk> wrote in news:v75to2$19lfk$ snipped-for-privacy@dont-email.me:

Personally I would always paint before assembly, I think of it as leaving the back of a cabinet with a rough finish, _I_ will know it's there and that I, in effect, had cut a corner. Will add to the preservation of the outer face too. Not too much of a faff either, set up trestles and roller paint, poss easier than once fitted when brush work would be required to fill in.

Remember though that once painted you will need to maintain . . .

I would go for either shiplap or T&G boards, the sawn feather edge boards tend to ripple over time and leave gaps. My local timber merchant sells both treated and untreated versions of 16mm thick T&G cladding and my self build shed I have only had a couple of issues where I know I did not compress the boards during manufacture. My Timber garage has shown no movement anywhere and is made of the same type of cladding.

As for preservatives I have diligently applied water based treatment to all cut edges and so far no issues. However, have a look at Rag & Bone Brown on YT he did a long term experiment using a variety of treatments with some surprising results.

No

Use a large roller rather than a paint brush. Use a primer/undercoat and a top coat. For outside I would use a solvent based paint

....BUT....

in my experience, and with a few brands of paint, it may be surface dry in the time stated on the tin but if you handle it (such as using it to clad the shed) you will find the paint very soft underneath the paint skin. You will end up with a poor finish as you break through the skin and get paint all over your hands. Last month I painted some boards and left them out in the bright sunshine sun for a few days and the paint hadn't cured fully in that time/temperature.

What advantage do you see in painting the boards before assembly to painting the shed after assembly?

PS. painting white outside this time of year seems to attract a lot of small flying insects. If they gt stuck in the drying paint DO NOT attempt to remove them immediately. Wait until the paint is touch dry, and then wait another day and then remove them with a soft wet sponge or cloth.

In message <v75to2$19lfk$ snipped-for-privacy@dont-email.me, TimW snipped-for-privacy@nomailta.co.uk> writes

Our builder had trouble with the farmhouse cladding (1995) shrinking. He resorted to pre-painting a batch. I have done the same on subsequent timber clad buildings. Three trestles with spacer strips between layers, you can get 20 or so ready for the next day. I use Sadolin woodstain but I have never tried white.

Watch out for the oil content if using Larch. Less knots but said to be tricky stuff to paint.

Treating all the cut ends with end-grain sealant is probably a good idea, plus all the t&g joints of any cladding with the same stuff, but finding a solvent-based end grain sealer on sale to the public is difficult, if not impossible.

The last tin of water-based end grain sealant that I bought was not very effective.

There was a time when OSB sheets always had green edges, presumably because this was the factory applied sealant and while OSB generally sheds water like a ducks back after a shower, the edges are vulnerable to swelling.

These days OSB(3) sheeting does not seem to have this treatment.

Bet you cannot build your shed as fast as this one was -

I'm quite impressed by some of the Zinsser products I've used in the past couple of years. I haven't used

Touch Dry 1 hour Hard Dry 16 hours at 20°C (full cure achieved after 7 days) Recoatable 3 hours