Built a deck this year. All boards pre finished with messemers. Glued to and screwed to wood framing w/ titebond sub glue. All miter joints got a #20 biscuit w/ titebond 3.

Now the callback. All the joints opened the same way. Open at the long point only. (All of them!, except the 2x4 top rail) I can assure you all the miters were prom night tight when I left, and I revisited the deck 3 months after completion and it still looked great.

Now it looks like a hack job, I'm going to fix it:sad:, but what caused this? What happened here? Major headache. :sad: Anyone dealt with this before? I've had joints open here and there before, but never all of them!!!!!!

Framing dried out and pulled everything with it.

 

Framing drying out, typically it would be a consistent gap. Not open on the long end of a miter.

Looks more of a deck board shrinkage issue. Maybe a little too green when installed, maybe winter time dryness, maybe both.

 

Looks like framing dried out and the boards are too tight at the joint. They are pushing against each other and out of perpendicular corner....or maybe the boards have expanded "widthwise" giving the same result (out of 90 corner).

 

Could it have racked?

 

Im always disappointed when I see my decks a few years later and they look like that

 

...

 

Perhaps the decking was too dry?

That would do it.

 

In your case wood picked up moisture & grew in plank width after install.
There's nothing you can do to prevent this! It's wood, & it's seasonal!

Around here it's always the reverse...the short point of cut opens up because lumber (mostly pt) is wet when installed. It's mostly about the change in plank width.

 

I'd brag to the customer about how what with all that rain the miters only opened up 1/32 of an inch. That's true craftsmanship!
You can redo it, but what will you do when that wood dries out a little and the inside of the mitre opens up? I understand wanting perfection, but fine antiques, and Steinway pianos, and floors, and everything else made of wood, moves. It's a deck.

 

Depending how it's fastened, I would be tempted to pull up one side of the corner at a time, backcut with a multitool, and finish with a block plane. Not for the faint of heart. Or sink an e-cut blade into the corner, using a 45 degree jig to keep it true.

Edit: Forget this. Backcutting would be dumb.

 

Shorten the edge boards a bit? Or run a Fein blade through the joint, using a guide? What do you think?

 

Built a deck this year. All boards pre finished with messemers. Glued to and screwed to wood framing w/ titebond sub glue. All miter joints got a #20 biscuit w/ titebond 3.

Do you mean glued to the framing or glued to each other? I always glue and screw the miters to each other but use very little fasteners to the frame. I also leave room for shrinkage, meaning when the boards shrink, they have somewhere to go. Try and picture your boards floating over the wood frame. If your fasteners are stronger at the deck framing than they are at the miters, then your miter will be the first thing to open up as soon as the boards shrink.

 

Yes and yes. I glue the snot out of everything with sub adhesive, even to metal framing.
For me, I've found less bananas and cups post install since implementing this practice. (Im talking hardwoods here)
Miters just get normal glue and biscuit.
......guess I need a domino

 

For future reference, you can also get out of that problem by avoiding that design all together. Looks like you set your rail posts to the inside of the frame. It leaves that miter pretty visible especially since it's by the stairs.

I do it like this, there's still a miter but it won't be visible even if there is shrinkage.

 

I'd brag to the customer about how what with all that rain the miters only opened up 1/32 of an inch. That's true craftsmanship!
You can redo it, but what will you do when that wood dries out a little and the inside of the mitre opens up? I understand wanting perfection, but fine antiques, and Steinway pianos, and floors, and everything else made of wood, moves. It's a deck.

Plus all that stuff stays inside in a controlled climate. This is exterior. Things move. I'd give the client a high five at how well its held considering the climate.
Or I'm sure one of the festool junkies will tell you that you should have used a domino. Haha

 

Or I'm sure one of the festool junkies will tell you that you should have used a domino. Haha

I have.......

This is exterior. Things move.

 

I'd cut them open and round over the edges.

Tom

 

Good aesthetic solution, as long as losing the biscuit isn't going to make things spring more. That's hoping that the biscuit isn't wicking water into the ends, too.

 

You do really nice work totes. I would not blame the joint openings on your craftsmanship. Miters will do funny things when exposed to weather and humidity changes. Each piece of wood will seek it's own final resting place. I am not a carpenter, but have spent many years woodworking. I tend to avoid miters altogether when making outdoor projects.

 

...

 

That's pretty much the remedy I've decided on. I'm going to pop the border pieces, cut the miters back, round over the edges and have a "celebrated" miter joint with an intentional 3/16-1/4" spacing. This way I can reuse the pieces, I will just fill the biscuit hole w pud....or 1/2 biscuit.

The stairs miters aren't that bad, leaving those as is. The issue was boarder pieces.

A lot of great responses, real food for thought. In the future I may eliminate the closed miter joint all together. They've been holding up pretty well with this material....until this.

Thanks all!~:thumbsup:

I've heard them referred to as "pillow joints".

Tom

 

I know people are going to call me a hack for this one, but those miters look well within tolerance for a deck. The shrinkage I have experience with PT have been far more severe than that.

 

I know people are going to call me a hack for this one, but those miters look well within tolerance for a deck. The shrinkage I have experience with PT have been far more severe than that.

They look a heck of a lot worse when you are standing directly over them, or when you are an overly self criticizing carpenter with obsessive compulsive disorder.

 

That's Ipe right ?

lately all of us have been experiencing more movement with SA lumber than we are used to. Not sure of the cause could be the guys over there are shorting up the air dry time.

Anyway with that material movement in the frame usually will not open up miters like that in fact I have never had it happen.

Pre finish was a bad idea if you expect the adhesive to work fastening to the frame, in fact pre finish on any decking is a bad idea. Normal plate jointing will not add strength to the joint they will just line up one side. The joint material has to be the same as the board for more strength.

One fix would be TB111/ sawdust, orbital sanding. SA lumber usually only moves one time.

JonMon www.deckmastersllc.com

 

That's Ipe right ?

lately all of us have been experiencing more movement with SA lumber than we are used to. Not sure of the cause could be the guys over there are shorting up the air dry time.

Anyway with that material movement in the frame usually will not open up miters like that in fact I have never had it happen.

Pre finish was a bad idea if you expect the adhesive to work fastening to the frame, in fact pre finish on any decking is a bad idea. Normal plate jointing will not add strength to the joint they will just line up one side. The joint material has to be the same as the board for more strength.

One fix would be TB111/ sawdust, orbital sanding. SA lumber usually only moves one time.

JonMon www.deckmastersllc.com

Brilliant !!

 

That's Ipe right ? lately all of us have been experiencing more movement with SA lumber than we are used to. Not sure of the cause could be the guys over there are shorting up the air dry time. Anyway with that material movement in the frame usually will not open up miters like that in fact I have never had it happen. Pre finish was a bad idea if you expect the adhesive to work fastening to the frame, in fact pre finish on any decking is a bad idea. Normal plate jointing will not add strength to the joint they will just line up one side. The joint material has to be the same as the board for more strength. One fix would be TB111/ sawdust, orbital sanding. SA lumber usually only moves one time. JonMon www.deckmastersllc.com

I respect your expertise John, but I'm confused as to why pre-finishing would be a bad idea . The board is sealed on all 4 sides in a controlled environment with ideal conditions. Just like siding which isn't back primed, cupping is more likely when only finished on 3 or less sides. The decking importer recommends a 4 sided finish with waxed ends. The dude abides.
The subfloor adhesive holds, big time. Maybe not that voc compliant Home Depot junk. I use the stuff that makes you light headed indoors, you can't scrape it off cleanly if you get some on the surface.
As for the joints, I figure a biscuit is better than none at all. It at least keeps them flush, and before this, closed tight.
Im glad to hear it only moves majorly once. Thanks

 

Built a deck this year. All boards pre finished with messemers. Glued to and screwed to wood framing w/ titebond sub glue. All miter joints got a #20 biscuit w/ titebond 3. Now the callback. All the joints opened the same way. Open at the long point only. (All of them!, except the 2x4 top rail) I can assure you all the miters were prom night tight when I left, and I revisited the deck 3 months after completion and it still looked great. Now it looks like a hack job, I'm going to fix it:sad:, but what caused this? What happened here? Major headache. :sad: Anyone dealt with this before? I've had joints open here and there before, but never all of them!!!!!!

Yeh but, when prom is over she's opened up like the Panama Canal

 

yeh but, when prom is over she's opened up like the panama canal

The dude ABIDES!

 

The dude ABIDES!

http://m.youtube.com/watch?v=sYsw0KVRjCM&desktop_uri=/watch?v=sYsw0KVRjCM

 

http://m.youtube.com/watch?v=sYsw0KVRjCM&desktop_uri=%2Fwatch%3Fv%3DsYsw0KVRjCM

Exactly

 

Decking laying flat to the Sun/Rain.

Water gets in from the top,is blocked on the bottom. Warpo city This has been common knowledge for years.
Many suppliers will tell you to prefinish and use the thinned down wax.Total Bunk ,Bogus, BS. They sell the wax and the finish. The wax will melt out quickly and not give any protection to the exposed area. It is used for the trip on the boat not meant to be exposed to the weather.

Not the same as siding at all. If you install siding like I do its a bad idea for that as well because the adhesive, no matter what kind, is not going to work.

Plate jointing with pressed/soft material adds no strength to any joint. They decrees the surface area if anything making the joint weaker. This has no effect normally on inside projects like they were made for in a controlled environment .

J.

 

The deck finish I use, is not some impenetrable water barrier. If water gets in, it gets out. (The front porch steps of the deck shown above were done by me in 2002. Same everything, and they look great, even with the first 3 steps within 18" of earth.)

I personally have had great success, and my decks and porches are holding up much better with pre finishing and gluing to framing.

You will get a better finish application in a controlled environment. period.

There are only two major importers of this decking in the U.S., both recommend a four sider finish with waxed ends. fact. Why would I not do it?

The importing companies have no association with the deck sealing company.

Back priming or back staining siding is a fantastic idea:thumbup:, and I don't glue my siding on. (Unless it's super small 2 inch pieces between a casing and corner board, ect.)

There's many things I do because I have to. I don't feel modified thinset under a floors tile underlayment is always critical. Some may call that "common knowledge". Many "pro's" skip the step. But it must be done on every one of my jobs, because EVERY tile manufacture demands it. Same line of thought here.
Until my decking importer and supplier tell me a one sided finish is superior, I feel it asinine to defy them.

...hard to defend my biscuit joints with the posted pictures..:no:

cheers,
totes

 

Your best bet for a miter is to follow the ol double up trick.

End grain will suck up glue making the joint starve, sooooo you double butter. Put on one coat ,wait, dab in another. I usta do this with red oak when I was doing cabinets and table tops.

Put a fastener thru the joint and hope for the best. Don't fasten the decking close to the joint.

J.

 

That's pretty much the remedy I've decided on. I'm going to pop the border pieces, cut the miters back, round over the edges and have a "celebrated" miter joint with an intentional 3/16-1/4" spacing. This way I can reuse the pieces, I will just fill the biscuit hole w pud....or 1/2 biscuit. The stairs miters aren't that bad, leaving those as is. The issue was boarder pieces. A lot of great responses, real food for thought. In the future I may eliminate the closed miter joint all together. They've been holding up pretty well with this material....until this. Thanks all!~:thumbsup:

I like that "Celebrated miter"