As soon as we had the floor up we started working on re-routing the ductwork. Though we are hiring out the plumbing and electrical I have experience working for mechanical contractors and can easily run ductwork myself. Just give me some sheet metal self-tapping hex screws and let me at it!
We needed to both add and re-route duct runs. Originally, there were only two runs for the master bedroom area; one under each window. With our new plan everything had to get moved. Unlike electrical or plumbing you can’t drill through floor joists with a 6” round duct you need to remove it back to the main and put it in a new floor cavity. That is why we went through all of the trouble to take up so much of the floor. Don’t get me started on those high velocity systems that can be drilled through floor joists. Just avoid those at all costs OK? Moving on.
Flannel Man had never worked with ductwork so our first duct run was kind of like Ductwork 101. We started with the easiest runs in the master bedroom where the floor cavities were relatively empty compared to the bathroom. The duct run under the south window was pretty straight forward.
Where we tapped into the main Flannel Man first tried a hole cutter that was in the ductwork aisle but all it did was dull and throw sparks. On the back of the package it clearly said for drywall only. So why was it being sold in the ductwork section? Who knows. For future reference the only ductwork hole cutter I’ve ever had good luck with uses a drill bit. With a dented circle in the main we turned to a spade bit and jigsaw for this connection. Then we added in a collar to connect the round to the main. It has bendable teeth on one side and a crimped round on the other.
When we got to where the fireplaces used to be and had angled floor joists. So we had to pop down below the ceiling which fortunately was a perfect height to tap into the supply main. We’ll eventually build a soffit around the duct to hide it but this whole nook of the basement will eventually be storage so it’s not a big deal. Of course in our rush to get it done we forgot to put in the damper at the end of run. Duh. So we had to rip apart the last straight section and reinstall it.
The second master bedroom was not too far from the old run so we were able to salvage a lot of straight pieces of ductwork. The boots and fittings get pretty tore up when we removed them. Everything was pop riveted together so it was a combination of drilling through those and just brute strength. The old ductwork was a nice heavy gauge (much thicker than today’s standard gauge) so I was glad we could reuse a lot of it. We removed the old run and patched the hole in the main then cut a new hole.
Because the main was run tight to the bottom of the floor joists we couldn’t just tap a 6” collar straight in the side like we did with the previous run. Instead we went with a top tap off boot which has a square end. Why square? Because cutting a square in a tight spot is a lot easier than a circle.
As we constructed the new and salvaged ductwork we sealed all of the seams with duct sealant. It’s a cheap and easy way to save energy and make your system more efficient. No need to dump air we’re paying to heat/cool in the floor cavity. I also sealed any seam in the existing ductwork I could get my hands on.
Before we could get the bathroom ductwork figured out the plumber came to do the rough-in. It was a nice change to pace to just hire a professional and let him do his job!
Progress after the first day.
Working on a new stack location (see the rags stuffed in the old stack and the new location in the upper left). On the right the main bathroom toilet.
Master bathroom. On the left a sink drain. On the right the toilet.
Almost complete after the second day. Initially, we really wanted all copper piping because we know how to work with it in case we ever need to change or fix anything. But the cost was significantly more for both materials and labor. So we ended up with a compromise of having extra copper used on the ends of the rough-in. From there we can use solid copper and easily solder on valves but the majority of the run is easier to install PEX.
Master shower drain.
New stack location in the 6″ wall.
On the third and last day the inspector came by an approved everything.
In the main bathroom we didn’t have to move the duct because one wall was staying. Yay! We also were able to fix the reason the basement bath (which is directly below this bathroom) has an extra low ceiling in the shower. Originally, the tub drain crossed over a duct which required the duct to jog down. Thus the claustrophobic shower I get to use everyday. With a little maneuvering we were able to straighten the elbows without even removing any of the duct.
That means that someday when we get around to remodeling the basement bathroom we can raise the shower ceiling. Someday previous owners we will have corrected all of your mistakes!
With the plumber gone and everything approved we were back on ductwork duty. Only this time we were in a real pickle. My plan got thrown out the window when we pulled up the floor and saw how many floor joists were already full of ductwork and later piping. With the size of the new master bathroom and the fact that it now had two exterior walls and two windows I needed to get two floor registers in the room which is difficult when bathrooms have limited floor area for a register. The old master bathroom duct would work it just needed to be extended a few feet. But on the opposite exterior wall there wasn’t anything and there wasn’t any way to add another run since every floor cavity was full with either ductwork, piping, or both. There was an existing floor register under the big 6’ slider that used to serve the bedroom but that is where our tub is going so that wouldn’t work. After a lot of hemming and hawing it finally occurred to me just change the basement registers around. So without having to change the majority of the runs we swapped the upstairs and downstairs registers.
The only problem was that the tub drain P trap came into that space and we had to cross the toilet waste pipe to get to the exterior wall. Hmm this calls for some creative ductwork…
Our nosy dog needs to be right in the action even if that action is on a plywood island in the middle of a construction site. See that guilty face? That is because 3 seconds after this picture she decided it was boring and wanted to get back off the island.
To get over the toilet drain we only had 3″ of height to work with. Two straight boots with a rectangular band bent to cover the joint. Lots of duct sealant and self tapping screws later:
Check out this sh*t! Ductwork WIN! Round to vertical flat oval. To round. To an offset elbow. To a round straight piece. To a boot. To an extreme short straight rectangular. To a boot. To a round straight. To an up boot. All done with the standard ductwork pieces Menard’s carries.
Yes this register will get less air because of the increased static pressure but I’m going to balance the dampers as best I can to overcome that and a low flow register is better than none at all.
Meanwhile the house is getting messier. Now I can answer all of Flannel Man’s “Hey Honey where is the _insert random tool here_?” questions with “It’s behind the couch.”