Friday, March 10, 2017

How I made a minisplit line chase out of vinyl gutter

When I decided to recaulk and repaint my lap siding I thought it was finally time to do something about this eyesore on the north side of my house.

Refrigerant lines, condensation drip, and control power for my
minisplit air conditioner inside wall unit
Because of my rigid frame construction I didn't have any way to run these lines inside the wall. In a tiny house the only wall is the outside wall and it sits right on top of double 2x12s. I can't exactly hog out a place for a fistful of copper and vinyl tubing to go up in there. And there's a beam over the plate glass windows with the same issue. So I made the air conditioning installer run the lines on the outside of the house.
This is the penetration through the wall
If memory serves I had him install this before I put up the siding. It's got spray foam all around it. With the refrigerant lines, wire, and condensate tube already coming through the 1x8 sheathing and house wrap I fashioned a kind of flashing around it when I put on the shingle siding. And I used caulk liberally all behind and around the pieces involved. It's not just put on at the end. And after 11 years it looks pretty waterproof at the penetration point.

The rest of the situation is pretty abominable though. I screwed something to the wall like a giant hook for storing ladders for the technician to secure the lines to when he installed them. Then when I put up the siding I replaced it with a small Simpson Strong Tie bracket and wired the lines to it. The algae growing on the insulation is pretty embarrassing.

This L bracket fiasco is my own doing
Clearly that pipe insulation needs to be replaced. And as long as I'm painting I should remove the insulation and paint underneath with less junk in my way. And then I should put the whole business inside some kind of enclosure.

I tried to figure out a way to do it with round aluminum duct. I was thinking of that kind that has a crimped seam on the long edge that you push together to make a cylinder. It would look cool, but I couldn't figure out how to do the L bend at the top.

So I went to work figuring out how to do it with vinyl K-gutter. This stuff is stupid cheap. 10' sections are less than $4. I bought one piece and brought it home to play with it. I was thinking I could just put it over the lines with the flat side against the house. But it wasn't deep enough. So I decided to figure out how to make a clamshell out of it. I got a preformed inside corner and an outside corner and some joiners and started figuring out how to cut it. 

Cutting PVC gutter

To make the clamshell work I had to cut the folded over parts off the bottom half of the shell. This is a two step process and takes two different tools.

To cut off the lip on the flat side I used a 4x4 clamped to a table as a rest for a jigsaw. I pushed the saw through the vinyl, then slid the whole business back, repeating until the whole length was cut.
Use a jigsaw and a block to cut the lip off the straight side
To cut the lip off the curved side of the gutter I used my fiber cement siding shear, the tool that caused me to be working on the house in the first place. Where it makes a dusty, un-caulkable cut edge on siding it makes a perfect edge on PVC gutter. No dust at all, unlike the jigsaw.
The fiber cement siding shear is the perfect tool for cutting PVC gutter
I had a formed corner piece for the outside of the clamshell, but for the part against the house I decided to just cut a miter. I left the stuff in my car too long and it got hot and warped. I had to clamp the flat side to the fence of my chopsaw with a piece of scrap wood to get it to stay straight while I cut it. I cut through the wood and the plastic at once. Worked good.
Clamp the flat side of the gutter to the fence of the chopsaw if it's warped
Once I had my two back pieces modified with the rolled edges cut off I had to figure out how to get the top part around the lines coming through the wall and around the bracket and everything. I used the jig saw to cut a hole with a slit for the penetration. And I worked out a way to cut out for the bracket. Then I realized it would be a hell of a lot easier if I just took off the bracket and put the gutter piece under it.

I finally had the long overdue inspirational thought, "What you need is a skyhook." So I went in the shed and got one. In this circumstance the skyhook is my big ladder with a standoff and a length of rope I use for tying boats to my car.
Skyhooks are real

Safely remove the old bracket. I caulked the screw holes.
I have a surprisingly vast selection of flashing in my shed. One piece of very wide aluminum bent in an L shape was meant for the skirting of the Spartan but it got wet while sandwiched with a dissimilar metal. It develop an impossible to remove discoloration. I had my sheet metal shop make it again for the Spartan but I saved the ugly one. Nobody will see the discoloration way up there. All I did was cut it to length. I thought I would cut the front edge later if I needed to, but I don't mind it sticking out.

In progress. Aluminum drip ledge moveable to ether side for access.
I have an electric sheet metal shear that works similar to the siding shear. I tried it on the vinyl too. It also works. But the siding shear is better on vinyl. I used the metal shear just for the aluminum.

I slipped the aluminum drip edge under the shingles above the chase. I'm going to call it drip ledge because it's massive. I secured the back piece of vinyl gutter to the wall with some sheet metal screws. I taped the slit in the end of the gutter by the hole for the penetrations. I also reinforced it with a piece of gutter cut from the same curved portion. My PVC cement was all dried up so I used the glue for the foam insulation. That product is the messiest glue I have ever used. I was so glad I was wearing disposable gloves.

I put the new insulation on the refrigerant lines. I glued all the joints unlike the original installer. I'm thorough that way. I'm hoping this batch of insulation will last a lot longer covered up. It's expensive.

The bottom of the vertical section is held away from the lap siding slightly. I shimmed it out from the ribbon joist of the house with a piece of PVC molding scrap I had in the shed.

Found a piece of PVC molding that fit just right

Found a long sheet metal screw that looked good for going through
to the 2x12 under the fiber cement

Two screws at the bottom and one up top seem adequate for the vertical section
I screwed the vertical section on at the bottom and at the top where it was on the shingle siding. There are no holes in the lap siding.

I decided I needed some reinforcement at the top of this whole business so I went rummaging through the shed looking for something that would work. I found a bracket of unidentifiable provenance that looked promising. I modified it with a hacksaw and then hit it with some primer since it was probably some junk from IKEA and would rust if I put it in the shade and then breathed on it.
Primer just in case 
This end reinforced
For the long end I wanted even more reinforcement, plus I had room for something with a long leg in two directions. I got a 5" galvanized L bracket at Home Depot, the only size that even comes in galvanized. I screwed it in place with Deckmate screws so long I think they go through the siding, through the sheathing, and into the 4x4 post that runs all the way to the roof. I like to use all the threads.

Big honkin L bracket
OK, so now what about the open end by the penetration? I decided the best thing to do there was cut a piece of wood the shape of the clamshell and screw the vinyl all around. I found a scrap of 1x8, traced around some gutter scraps, cut it out with the jigsaw, and then primed it. It didn't fit that great in place because screwing the gutter to the wall made it a lot less bendy. I ended up using a lot of backer rod and caulk and more paint to make it look good when I was done.

End capped with wood didn't want to fit tight
The other end has the factory made inside corner. I put the fitting over the big L bracket and under the back of the clamshell. Then screwed them together with 1/2" long stainless steel #6 sheet metal screws. The bracket is just for defeating gravity. Nothing is attached to the top of it at all. 

The weather stripping stacked up at the back of the chase in the photo below is to stop the drip ledge from settling down so much it can't drain. On a sunny side of the house I would expect lizards to go in between the chase and the drip ledge, but in full shade they probably won't.

Clamshell fastened together on top with screws
After I was done connecting the front and back of the clamshell together on top I ran two screws through the aluminum into the vinyl at the front edge. That secures the front section to the wall without depending on the back piece of vinyl. Also stops wind from lifting the aluminum ledge.

Drip edge secured to front of chase with sheet metal screws with rubber washers
The end of the vertical section ends in a molded outside corner. I drilled a hole for the condensate line to come through. The post in the photo below is a reused gate post, thus the hole. The sole purpose of that post is to hold the hose bib. The footings around the posts of the house make it inconvenient to run the pipe up them. This existing post conveniently allowed the perfect amount of clearance for the chase.

Condensate line comes out a hole in the last fitting
I needed the end of this outside corner open to be able to work the hose bib handle. I shoves some extra foam insulation up in the end of the chase to stop critters from going exploring up there.
The west side of the molded outside corner is open

Along the flat back side I didn't need many as screws. Painting partially done
I secured the clamshell halves together with plenty of the stainless steel screws along the overlapping edges. I used about twice as many on the K profile side.

I put a lot of the short stainless steel sheet metal screws on the curved side

Stand back and admire the work 
After I finished the chase I sent my brother photos. He told me I need a trap for my condensate line because wind washing makes biofilm grow. I rigged up something out of PVC parts I had on hand. It still drips into my reused toilet tank condensate catcher. If I decide I like keeping a little vessel constantly full of water right there I can paint it to match the post.

I was happy when I was done and I could clean up all the PVC dust in the shed once and for all. I was looking forward to painting the lap siding, a job I could do listening to podcasts. 

When I stood back and looked at that side of the house that big white thing on the wall just seemed unnecessarily prominent. I decided to paint more of the trim around the windows white, to draw the eye away from it. I guess it's better, I don't know. 

Finally I replaced the hose hanger on the side of the house and I call it done.

It should be straightforward to take the chase apart if the refrigerant lines ever need to be replaced or serviced. I shopped for little plastic rivets to use instead of stainless steel screws to connect the halves. I didn't use them for two reasons. 1. They are stupid expensive 2. All HVAC techs have a screwdriver, but rivets might stump them. It's entirely possible this piece of kit will outlive me. If nobody thinks to look at the web archive to see how I built this they need to be able to figure out how to take it apart just by looking at it.

In conclusion: DO NOT ATTEMPT. This project came out fine. I didn't hurt myself. I didn't spend a ton of money. But it took me a ridiculously long time to do this, like three entire days and multiple trips to Home Depot. I guess if I'd had instructions I could have gotten all the stuff in one trip, but the figuring it out with the junk I had on hand was slow. If I'd spent three days figuring out how to rough in these lines inside the wall by bumping out the inside corner by the door to the bathroom it would have been a superior solution. But building a time machine to go back to 2005 was totally beyond the scope. 

Bill of Materials:
$15.92 10' gutter sections $3.98 x 4 (it's so cheap I got a whole extra one just to practice on)
$13.05 K-Style joiners $4.35 x 3
$6.54 1 inside corner
$6.54 1 outside corner
$35.97 Pipe insulation
$7.98 Pipe insulation adhesive
$3.51 Stainless steel screws
$3.18 Galvanized 5" Angle bracket

Total chase cost $92.69

Add that to the cost of the house caulking/painting project from the last blog post

Painting Project
$6.28 Big Stretch Caulk
$27.98 1 Gallon of Satin House Paint
$5.97 Low grip painters tape
$3.98 Paper drop cloth to cut up and tape over the orange part of the house so I didn't splash it with paint.

Total repainting cost $44.21

Grand total of 2017 Spring Project

Tiny house = tiny maintenance costs 

I can paint my whole house with a gallon of paint. That's never not going to be funny to me.

Regret for my Past Self: Correcting Caulk

When I built my tiny house by myself I used a Snapper Shear to cut the fiber cement siding. I love this tool because it's quiet and feels relatively safe compared to a circular saw with a fiber cement blade. But most production carpenters don't use this kind of tool because it costs over $300 and it's what Alton Brown would call a uni-tasker.

The video talks about the advantages of the tool, but leaves out the main problem. A saw leaves a sort of burnished edge. The shear basically works by pulverizing the product. It leaves the cut end very dusty. I did not realize at the time this was going to be a problem in the future, but I should have. Caulk can't stick to dust. Where the factory ends butt up against the corner boards the caulked joint looks perfect. But the ends I cut, the caulk didn't stick. Little cracks appeared. I should have washed the ends of the siding in a bucket of water and then let them dry before caulking.
Crack between caulk and cut end of siding
The weather has been pretty good for working outside so I decided it was time to take care of this problem. I worked up a special tool for cutting the caulk at the corner board so I wouldn't go too deep and cut into the house wrap. I used my straight mat cutter with a 3" scraper blade modified to fit it. This turned out to not work any better than my regular utility knife so I'm not even going to put up photos.

The most useful tool was a dental spatula I got as part of a $5 set from PJ Tool and Supply, the same place I got some hemostats, also useful.
Here's the useful dental spatula

I really wore down the end of this little tool
After I cut the caulk where it was very strongly bonded to the corner boards I got all the old caulk out of the joint.
Caulk didn't fail, just the bond to the siding
I hoped the caulk would take most of the dust with it, but it sort of didn't. I could make dust come billowing out of the crack with a little brush I got at the grocery store by the dental floss. I washed the whole house down with a scrub brush and a hose after I opened up all the cracks. Then I scrubbed out each little crack again with the brush until I could not make any more dust come out.
I cleaned the ends of the siding with tiny brushes for cleaning braces
I used Dap Dynaflex 230 caulk when I built my house. I like it. It was my fault I had to redo it, no fault of the product. But for the sake of curiosity I wanted to use a different caulk for the replacement. I did some research and found some people on the Fine Homebuilding forums like this stuff called Big Stretch by Sashco. I made a special trip to Lowes to get some Big Stretch since they don't carry it at Home Depot.

I actually don't like it as much as the Dap. It feels kind of gritty. And it didn't fill the gaps as well. Some places it shrank so much I had to caulk again after I painted to make it look consistent. Time will tell how it does in the long run.

Tiny house benefits. All the caulk I had to replace only comes to 115 grams
Because I'm a woman who has eyes I put down a drop cloth while I dug out the old caulk. I dropped the pieces into the same apron I use to pick blueberries. Any stuff that fell on the cloth, I scooped it up before I moved to the next corner. At the end of the job I had about 115 grams of wasted caulk. This is a data point without a purpose.

I was able to recaulk all these joints with less than one tube of caulk. I bought one gallon of paint and repainted the lap siding on three sides of the house. I still have over a quart of paint left. Tiny houses rule!

I repainted the siding on the front porch when I built the porch and turned the door around to swing out. That was 2013. I changed from flat to satin paint on the front porch then. So this time I made all the lap siding satin. I left the flat paint on the shingle siding and overhangs. The caulk seems fully adhered to all the joints of the shingle siding even though I cut the top edge of that with the shear to fit the angle of the gable. I would say it was due to not being in direct sun, but on the north side of the house the lap siding caulk joints failed and they are in the shade all the time. Perhaps larger joints don't exert as much pulling force against the bonded edges. My corner joints are pretty tight, but they are within the specifications of the product. I left bigger gaps for the shingle siding.

Oh, I just figured it out sitting here typing this. The expansion and contraction of a long siding run changes the size of the end gap more than what would happen next to a narrow shingle. Even the short pieces of lap siding between windows are longer than the widest shingle. Expansion and contraction is cumulative.

Next blog: The rabbit hole I went down to pretty up the lines to my minisplit and a new use for the siding shear.