Hello all, I'm planning a glulam barn frame to go up in place of an old, crumbling, partly collapsed oak frame.
During my planning phase I've been investigating the best way of setting the posts. I've seen many instances where suggestions are: 1. dig a 1m deep hole 2. place 4-6" gravel in the bottom. 3. install and plumb post; pour in concrete and allow to set.
No issue with that; nice clear instructions. My concern is that the wood will take up the concrete's water and start wood rot.
I was thinking of either: 1. wrapping bottom 1m of post in fibreglass or; 2. painting bottom 1m of post in resin roof repair such as Everbuild Evercryl.
Yes, use this stuff: http://www.makewoodgood.com/catalogue-2 ... xy-sealer/ It's expensive, but will offer more rot protection for your money than anything else you will find. If you were to put the Evercryl or fibreglass wrappers around the wood, you will find that they: Don't bind particularly well to the wood long term Don't move particularly well with the timber, which encourages their separation from the outer fibres of the wood. Given the cost of trying to sort out a rotten glue lam frame later, I would have no hesitation in using CPES here. There is a whole wealth of evidence out there from the wooden boat community, see here for a bit: https://www.youtube.com/watch?v=6WF0Bqcvvsg CPES will penetrate into the timber, and will make the bottom of the glu lam beams effectively impermeable to liquid water. This will allow the beams to breathe normally, and thus you will not offer the ideal conditions for rot to begin.