Simpson Duravent Install

I feel like I’m far enough along in this project I can comment. My biggest pet peeve with this entire project at the moment is the fact that all the brackets want to be screwed into drywall and drywall simply isn’t rated to support 60lbs to 120lbs of pipe. So you end up using a 2×4 to give the bracket something to hang out on and distribute the load, and it’s not happy being on there. Not only do you lose an inch and some change, but now the rest of your measurements are thrown off.

My second pet peeve is that when you adjust the adjustable bracket because you mounted it on a 2×4 and thus threw off all your measurements, you will invariably not line up with the holes. They’ve got rails cut in it so you have some adjustment, but you really need the entire line cut or they should just tell you to be ready to drill your own holes. This “it’s adjustable, lol!” and then only giving you a quarter inch or so of play on each side isn’t cool. I ended up drilling holes to adjust it between two stops.

The lock rings are terrible. The top of the T has a lip and a smaller, more subtle lip. This is where the locking band goes. It’s not explained anywhere. I compared it to the other T they sent me and they were identical. This is just something they built into it. Also it’s possible to overtighten the lock ring, I tightened the crap out of them then I backed it off a bit. Remember – the pipe wants to expand when it gets hot. On the other hand your support bands are (correctly) made from the same steel the pipe is, so the support bands expand with the pipe. You also don’t have to worry about annealing like this.

The support band for the elbow needs a redesign. I would have killed for a simple eyelet which would let me choose the angle I wanted the band on. As it is currently done, the band has two arms come off of it and the amount you tighten the band determines the angle of the arms. I ended up simply screwing wood blocks to the drywall to support it and these blocks took up the angle off the studs which the bands required. This is simply a crap design and there’s 100 ways to solve this problem. Basically a line tensioner (the twist kind you see on fences and clotheslines) with another strip of metal coming off that would have taken care of both the angle and offset while still providing adjustable support without having to redrill the holes (which I did) when you realize the angle is subtly wrong. I was sort of tempted to cut it and make my own but any modification to UL approved equipment voids the UL rating. That and I didn’t know that the sheer force was for the existing stuff, so I decided that discretion was the better part of valor and just did the wood framing.

OK so what are the plusses? For one, the pipes are shipped lightly greased. We’ll see if this cooks off or not but it makes assembly easy. The twist lock thing works generally well with one caveat: The pipes don’t always center themselves when you do it. More than a few times I’ve reseated a pipe and either had it slightly off or had it bind up on me “unscrewing” it. The reason is that the threading on the pipe sections tends to overlap both ways because it’s not a real thread. While the design works and I’m sure it’s cheap to make, it’s not the best design in the world. There’s enough overlap between each pipe however that not having it entirely seated isn’t a show stopper, this is a good design because you expect to need a bit of here or there when working on the pipes and again the pipes will expand at different rates.

Also conspicuously missing is caulk. Would it have killed them to include caulk for the roof penetration?

All in all this is worth about 3.5/5 stars. It’s not perfect. It sucks less than other kits which require bands every section. It could have been made to be lighter and they could have done better on the hardware (one of my lock rings was entirely missing a screw). The T support is just weird that they didn’t think you were going to put it on a 2×4. On the other hand it’s entirely serviceable and tolerant of the abuse I’ve put it through doing 100 test fits. If I were to do another stove install, this is the kit I would suggest.


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