Braces that will be exposed on both sides to the weather ie; on a farmer's porch

[mmhailey]

Does anyone have any experience with normal brace pockets when they are used in an area that might get windblown rain. It seems to me that getting water into the joint probably would lead to joint failure at some point.

This application is on a porch, and while covered it would definitely occasionally be in for some severe wetting. Possibly associated with later freezing.



 

[D L Bahler]

There are a couple of approaches

1. slant the bottom of the brace mortise and tenon, so that water cannot stand inside.

2. Bore a slanting hole into the mortise from the bottom.

And DO NOT use caulk to seal it -this will work for a while, but once the caulk loosens the slightest bit, which it will due to wood movement and flexing at the joint, it will hold water making things worse.

Also, if you put a very slight radius on all of the corners of your brace tenon, it will be less apt to hold on to water.

[Jim_Rogers]

1. slant the bottom of the brace mortise and tenon, so that water cannot stand inside.

In a recent article in Timber Framing, the magazine put out by the guild, it was mentioned that this is a good solution to an exposed brace.

Jim Rogers

[D L Bahler]

All I've gotten around to reading in that so far is the article about that Chinese temple.

But I am familiar with a lot of water management solutions from German style framing, which typically leaves the frame totally exposed to the outside, and often has elements such as bracing for enormous eaves that are completely exposed.

And while we're talking about it, if your post sits in a sill underneath, don't forget to make a way for water to get out of the post mortise

[laffs]

how about a weep hole to the mortise ? You may have to clean it out now and then because of bugs, or give it a shot of incecticide to keep the bugs out.

[krusty]

just like anything log or TF.....a proper overhang of the roof will make a difference. a nice 12" or 16" overhang should suffice. I know on my porch I get driving rain a couple times a year but am sure it will survive a few generations.

[mmhailey]

Thanks for the suggestions. The problem I keep running into is that because of the roof configuration I really can't get much of a overhang on the eave sides of the porch. In the marine environment wind, rain, freezing, thawing etc., I am thinking this would be the first place I would have a problem.

I am leaning toward housing the braces ie; 5 1/2", then rather than cutting a mortise use galvanized or Stainless lag bolts. Certainly not traditional, but I wouldn't have to worry about rot in an enclosed area, with no way to inspect. Keep in mind I am also using rot resistant timbers. They are Alaskan Yellow Cedar, which is very similar property wise to cypress.

[D L Bahler]

The use of lag bolts introduces a whole other level of problems though.

Moisture will condense of the surface of steel due to its conductive properties, and capillary action will draw surface moisture in. Also, the thermal conductivity of steel can potentially condense moisture out of the wood, collecting on the surface of the steel and thus introducing excess moisture where the steel and wood are in contact. This causes rot.

It is for this reason that I try and never use steel connections. While yes, they are stronger initially these conflicting properties of the 2 materials will cause them to destroy each other over time.

Personally, I would go the route of a sloped mortise bottom, and perhaps you could even cut a slight channel in it to ensure water will drain out.

[Brian_Weekley]

This might not be the look you're going for, but can you side the exterior of the braces?  It would certainly protect the brace joints from water.