A suitable wood preservative for roof rafters?

[epsilonGreedy]

After reading another thread on BuildHub I get the impression there is a regional split between manufacturing roof trusses with treated wood or not. Mine are untreated so I am thinking about applying a coat of preservative before felting, perhaps just the rafter tails that will support the wooden boxed eaves.

 

Is there a dependable wood preservative brand? They all seem like a variation of snake oil potion to me.

 

So far I have concluded the best wood preservatives include some extra chemicals to protect against wood boring insects.   

[SimonD]

Many chemicals loose their potency over a number of years but Boric Acid based preservatives have been used for a long time and even in ship building. It gives good long-term protection and is relatively safe. You can buy either Boric acid power or ready made solutions and simply spray/brush it onto your timbers. If you're worried about timber being particularly exposed to moisture, you can use a Boric acid gel for extra protection.

 

HTH

Edited April 20, 2021 by SimonD