How to hide pipes and ducts
Q: DoI have a conundrumfor you! Amajor remodel is about to happen atmy home, and alreadywe’ve got a problem. Anewmaster bathroomis being created in a second-floor room, but I can’t figure out howto get the drainpipe down to where itwill connect to the rest of the plumbing drain pipes. How have you done this in the past on your jobs?
Butwait, there’smore! We need to get larger ductwork up to the second floor aswell!
A: I see these tough situations in new homes aswell as old ones. As a master plumber, I drawa lot of plumbing isometric and riser diagramplans for homeowners so they can get a plumbing permit. WhenI study their floor plans, I’m stunned to see howmany architects don’t think through howpipes need to get fromone level to the next with as few bends as possible.
This is one reason I feel that architecture students should be required to have construction, not drawing, co-op jobs for half of the time they’re obtaining their degrees. They need towork on actual job sites side by sidewith carpenters, plumbers andHVAC tradespeople. Whenthese young, fertile minds actually have to figure out how to make thingswork in the realworld instead of on a computer monitor, their plans will be so much better in the future.
The architects of old often solved these issues with strategically placed walls, pantries and closets on the level belowwhere the bathroomwould be. Awall on the lower level might be 6 inches thick for piping, although 8 inches is far better.
An architect mightmake one or more of thewalls of a closet thick enough to accommodate the pipe or ducts. Afalse cavity can be created in the back of a closet by adding a second wall. This cavityworks well to get a large duct trunk line fromone level to the next.
Corner pipe chases are also greatways to disguise pipes or ducts that have to go fromone level to the next. To balance out the look inaroom, youcan always add a faux one in another corner. In the past, I’ve even built a long shelving unit that extends down fromthe ceiling about 16 inches that spans the space between the needed pipe chase and the faux one. All sorts of decorative items can be put up on the shelves, and this takes your eye away fromthe pipe chases. The average person thinks the chases are needed to support the giant horizontal shelf.
It’s important to have some flexibility with the plumbing drain line. Atypical residential bathroom with a toilet, shower, bathtub and even two vanity sinks can be connected to one 3-inch pipe.
This pipe can run horizontally a significant
Be aware there are very strict building code requirements and structural best practiceswhen it comes to creating holes in floor joists for pipes.
distance, even up to 25 feet or more, before having to turn downto get to the next level. You can even have several 45-degree fittings in this horizontal run. Just be aware this pipe needs to slope 3⁄16 inch for each foot of horizontal run so the liquids in the pipe don’t outrun the solids.
Knowing this, you may be able to extend the drainpipe to another roomon the lower level away from themaster bathroom above. The pipe chase might end up in the corner of some other roomor even be inside a closet. It’s all a matter of howlucky you arewith respect to the run of the floor joists belowthe new master bathroom.
Be aware there are very strict building code requirements and structural best practiceswhen
it comes to creating holes in floor joists for pipes. Notching floor joists is never to be done, as it weakens them. Holes drilled through floor joists need to be certain sizes and in very specific locations. The building code addresses these and there are quite a few helpful online guides you can reference.
If you’re using PVCor ABS plastic piping for the bathroom, be sure to install sound-deadening insulation around the pipes in both the ceiling and the vertical pipe chase once everything has been leak tested. Thewater flow
ing through and down the plastic pipes vibrates them with ease. This iswhy it sounds like awaterfall is in yourwalls if no insulation is present. You can eliminate this noise using no-hub cast iron drain pipes.
Your ductwork challenges are the same as for the plumbing drainpipe, only bigger. Ductwork is much larger than a plumbing stack and needs far more space. You may need to construct soffits in a roomand disguise these creating a trayed ceiling in a room or two so the soffit doesn’t stick out like a sore thumb.