Advice needed on how to fix some water damaged wood on wood posts in the outdoor deck roof. As it rained last night, I found the cultript. Water is leaking through the roof on the spot right above the damaged post. I got up there and checked the post. The damage doesn't seem to be too deep. In fact the post seems solid when poked beyond the first 2 cms of damage. So similar damage on the other side of the post. Damage only on the outter section on one side of the post. I'm a bit of a novice at this sort of repair work. Any tips on how I can approach treating the damage once I've patched the hole in the roof itself. I assume I'll need to remove the damaged wood (which only seems to be a couple of cms deep) and apply some sort of a wood sealant. Many thanks.
Morning Chat @Chat
Is it just this one spot - or is there another area of concern to the left of your photo?
Is the wood Oregon?
Thanks for the response @Noyade. Yes, that spot also has the same issue but not as severe. Not sure of the type of wood. I just know it's a very tough wood. It's a decent sized deck roof. This water damage issue is only present in the one area I've noticed.
Hello again @Chat
To be honest, I'm an amateur DIY'er - and you'll get better advice from Mitchell, Eric and others.
Firstly, I think you need to find out where the water is coming from. Cracks or imperfect screw seal?
But, we inherited something similar when we bought our house many years ago and the pergola was never covered.
To me Oregon didn't appear to be a durable wood exposed to the elements.
With an area like yours, I rebated the rotted areas and inserted hardwood pieces.
Later when I covered it with corrugated iron and knew I would be walking on the roof, I doubted the structural integrity of such a patch.
So I added a second hardwood beam - and bolted it to the original Oregon beam.
The noggins (correct term?) of course had to be removed prior and shortened.
Most likely overkill - but just a late morning thought. 👍
Welcome to the Bunnings Workshop community @Chat. It's wonderful to have you join us, and many thanks for your question about repairing a roof joist.
If you were to have this damage accessed by a builder, I would say that the answer you'd receive is that the joist needs to be replaced. It appears that at least a 5th of the joist is completely disintegrated, and no doubt the next 30mm down from that is compromised. What was likely close to a 190mm joist is now a 140mm joist with unknown internal damage. If your new 140mm joist cannot span the length, it's at risk of collapse. Not many people pay extra to over-spec a roof when constructing one. So, the materials used are generally the minimum needed to span distances. If the 190mm was at max span, then the 140mm cannot support its own weight, let alone the roof material.
Check out this table below, just as an example. If that 190mm timber was capable of spanning 4500mm, once it's rotted away to 140mm, it can now only span 3400mm. That's not even taking into account that the beam is rotted and suffered unknown damage.
It's my opinion that the beam is structurally compromised, and the damage seen is not just cosmetic. Unfortunately, you've caught the damage a little too late, and it's now time to replace the joist. It's not worth risking your and your family's safety to patch up a compromised beam.
Please let me know if you have any questions.
Thank Mitchell for a detailed response. I'll have it assessed by a builder.
Keep us updated @Chat; I'll be keen to hear the results.
Just to add to the suggestions made, I recommend using Bastion Type 17 Polycarbonate Roofing Screws - 100 Pack. They use EPDM washers that will provide superior longevity against the weather. If you wish to take it one step further, I recommend putting Selleys 290ml Clear Storm Waterproof Gutter And Roof Sealant on both the old and new screw heads for added weather protection.