Common problems with Central Oregon decks

Well the last couple of weeks have been kind of intense. We have been rebuilding parts of a deck that was originally built in about 1990, and we have been coming across rot and termites and just about every problem you can have with a deck. It's also nestled among boulders and the specifics mean we are "scribing" the decking to the stones. That means we have to transfer the shape of the stones to the decking boards... maybe I should just show you a photo.

As you can imagine we have to pull out just about every trick in the book and tool that we own to pull this off. Transfering that complex of a shape accurately isn't an easy task, and at the end of the day it mostly comes down to getting it close and then shaving tiny amounts off until you have whittled it down to where it should be.

All that as an aside, this project has been a real reminder of some of the main problems we see on older decks here in Central Oregon. There's a few videos on instagram of me describing what is going on if that's more your style, but either way it's good education to have as a Central Oregon homeowner. I expect that you'll be going out to look at a couple of things on your deck after you read this!

Poorly detailed ledger connection: This is the main place I see rot happening on Central Oregon houses. The "ledger" is the lumber that is bolted to the house which the joists connect to. This ledger should be bolted firmly to the house as it carries all the weight of the deck. It should also be installed in a way that doesn't trap water behind it... there are a few ways to do that depending on application. Many ledgers on older decks are simply nailed to the building, tight to the siding. For one thing this isn't strong enough, and I've seen a number that are pulling away from the building. For another, it traps moisture from rain and snow against the siding of the house, and trapped moisture leads to rot. These ledger connections are so critical, especially on balconies... If you have a balcony on your house and it's not fairly new it might be a good idea to poke around and see if you notice anything concerning.

Yuck

Poor runoff management and ventilation: There were two locations under this deck where the ground had a small hollow and was allowing water to puddle. Also the decking boards had been installed tightly together and the entire perimeter of the deck was enclosed. Either one of these problems on it's own might not be too bad, but both of them together is a killer. A few years ago we worked on another deck with similar problems which was only two years old at the time and the joists were already rotting. If the water can't drain and it also can't ventilate it makes a high moisture environment. It's really best to have breathability even if the water is draining away well. It's common for "green" decking to be installed with no gaps, with the logic that it will shrink as it dries. This is ok, but if you don't manage your moisture well it can actually expand, I have seen decking that expanded so tightly there were puddles of water on top of the deck.

Non-treated lumber, undersized lumber, and joists spaced too far apart: We will typically use pressure treated lumber for any deck, although for code it's only required within a certain height from the ground. We've seen quite a few decks with regular kiln dried lumber for framing even when it is close to the ground. This is less than ideal but if you combine it with bad moisture management you can have a real problem. I've also seen lots of them with joists that are spanning too large distance for the size of the joist, and quite a few with joists spaced wider than they should be. It's common to see joists under 2x6 decking spaced at 24" inches which is ok (though not if you want to upgrade to a composite deck) but I'd prefer 16" regardless. I've also seen them spaced as wide as 48" which is really scary. It's reasonably common for people to ask us to just replace decking and not deck framing, but often the deck framing isn't spaced properly for the new decking.

Weak railing connections and railings with large gaps: Any deck over 30 inches tall requires a gaurdrail. Alot of the older rails were done with 4x4 posts, 2x6 stretchers, and 2x2 balusters. Many of them have weak connection at the posts and the balusters are spaced too far apart. This is much more of an issue with a 2nd story deck or a balcony obviously. If you are concerned about yours, sometimes a few strategic bolts is an adequte fix but we are here to take a look if you'd like.

I'm not trying to be a bummer about any of this. It's good knowledge to have if you own a home here. And if you do have any of these issues, it's always best to fix them ASAP rather than waiting. Particularly if you have rot hiding behind that ledger. Most of the time when we have dealt with it it hasn't penetrated into the actual framing of the home yet, and we have been able to replace the sheathing and siding. But the longer you leave it the deeper it will go. I think it used to be a common attitude that things will dry out in Central Oregon and that it's not necessary to put much effort into moisture management because of our dry climate. Also I think decks on a lot of older houses have been DIY'd in a time when it was a little more difficult to get good information on how to do it right.

If you have concerns we are available to take a look. I'm always interested in offering practical solutions to any of these problems if possible. Obviously we are available for repairs and re-builds but I'm also available just to give advice and suggestions.

Have a great long weekend!

-- Caleb