Larch - as a deck - to treat or not to treat

[mattice]

I'm half way through installing my English larch deck. I chose it because I wanted a compromise between the cost (or ethical sourcing) of hardwood and the thin green tanilised stuff that adorns the sheds.

I'm impressed. Solid, heavy, straight, good looks, sound knots etc. Our intention is to let it gracefully silver rather than preserve the pinkiness of it.

Our supplier suggested no treatment required due to the high resin content. It also seems to be the cladding of choice in marine environments...

Shall I take my chances or whack on a few tins of ronseal total wood preserver? I really don't want to go down the oiling, waxing staining route if I don't have to - nor do I want to slow the ageing process.

I guess I'm only faltering due to a wet and miserable bank holiday where everything seems sodden.

Thanks in a advance.

M

 

[foxhole]

leave as is.

 

[AronSearle]

Larch is slightly durable, so it will need some preservative if you want a long life.

 

[Harbourwoodwork]

Larch fares well in a marine environment and not in fresh water Trada rates it as moderately durable 10-15 years in ground contact.

 

[mattice]

Thanks, it's all off the ground and there will be no pooling water. I wonder weather something like teak oil will give it some water and dirt repellence, yet let it silver with time?

I've used ronseal total wood clear preserver for a lot of projects but I'm usually painting afterwards. It does seam to be quite clear, and I know it is not water repellant, but would it prevent the silvering process i.e. does it block UV? Or put it another way, will it have any adverse effect?

Thanks for comments so far.

 

[Harbourwoodwork]

Not all Teak Oil has UV protection the non UV oil is available on amazon for about £30 for 5LTS

 

[joe-90]

Whenever I've used oil outside its suffered from that dark blue/black ink stain problem.

 

[AronSearle]

Some oil's can contribute to mould, or simply not prevent it, lot's of variables.

Use a coating with both a pigment and fungicidal additives if you want a decent life, anything water repellent will help keep it dry and help reduce the risk of rot if well maintained.

Clear finishes will tend to not last long (but do no harm).

Do nothing and it could still last a good 10-20 years if it is properly above ground as you say, depends on if you think that is a long or a short time.

Larch fares well in a marine environment and not in fresh water

Different environment and decay mechanisms / different use / different practices.

Trada rates it as moderately durable 10-15 years in ground contact.

No, slightly to moderately durable, which is less than that life in ground contact, larch fence posts have failed in half that time.

 

[mattice]

thanks all, I emptied a tin of total wood preservative because I had it..... straightforward.

A few days later did a test patch of osmo teak oil. It's still sat on the surface wet, 72 hours later. I only headed in this direction to help with cleaning really. Going to leave as is now.