Small Modular Cabin Construction: Water

We got to go down to Due West and see our cabin. We took over a hundred photos, plus they gave us photos of the construction. This post is about the plumbing system construction.

Cold & Hot Water Supply Detail
Plumbing Isometrics and Details
Westwood Cabins Creekside Manor 3016
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This is the water plan. You don’t need to click, I have the plans larger next to photos of the work below.

Drain/Waste/Vent Detail
Plumbing Isometrics and Details
Westwood Cabins Creekside Manor 3016
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This is the sewer and vent plan.

Have you ever wondered why plumbing has vents?

Why are plumbing vents necessary?

The simple answer is physics. Have you ever stuck a straw in a drink, capped it with your finger and pulled the straw back out? The liquid stays in the straw because you’re blocking airflow, preventing the air from pushing the liquid back out. Uncap the straw and gravity takes over and air replaces liquid in the straw.

Why the Analogy and What Do Plumbing Vents Do?

This may come as a surprise, but plumbing requires air to work its best. By having access to the outside air, sewer gas can escape and air can enter the pipes when someone flushes or uses a drain.

Take a toilet for example. Right below or behind the porcelain throne is a U-pipe that seals access to the sewer with fresh water from the tank. Next is the S-trap, also known as the plumbing vent. Every time a person flushes the toilet air rushes in from the vent to maintain neutral pressure in the pipes, and gravity does the rest.

Plugged at the U-pipe, the fresh water blocks sewer gases and lets them harmlessly leak out the plumbing vents. Every plumbing fixture needs to have a vent to work properly. Bath tubs, toilets, washing machines and kitchen sinks need the biggest plumbing vents.

Black Diamond Plumbing & Mechanical

Kitchen

The kitchen plan has hot and cold water to the sink, hot water to connect a dishwasher and cold water for the ice maker.

Water Hammer Arrestors

The plans say we will have water hammer arrestors. You can see them further down this page on the photo of the laundry room.

Water hammer arrestors to be installed where quick closing valves are utilized (i.e. dishwashers, clothes washers, ice makers, or other quick closing devices with solenoid valves). Arrestors must comply with ASSE/ANSI 1010 and must be installed in accordance with the manufacturer’s instructions.

What are water hammer arrestors? Have you heard pipes clunk or shake when you turn the water off fast? A water hammer arrestor acts like a shock absorber. It is a short piece of pipe with an empty chamber that some of the water can go into when you shut the water off so that it doesn’t all go into the pipes and make a clunk.

And yes, it is “arrestor” with an “or” although autocorrect keeps autocorrecting.

The kitchen sink gets hot and cold water.

Plastic water pipe and fittings: CPVC plastic pipe shall be used for all cold and hot water supply piping, except that exposed supplies to plumbing fixtures shall be C.P. brass. Fittings to be solvent type.

Cold water line to the ice maker.

This is the plan for the kitchen drains. After the house is delivered, a local plumber will connect the lines to the sewer.

Kitchen Sink: shall be ledge type, double bowl, 20 gauge, type 302 stainless steel sink, self-rimming Elkay no. CR-3321, overall size 33″ x 21 1/4″ x 7″ deep with single lever deck mounted swing spout faucet, Delta no. 400 lf-wg, with 2.0 gpm aerator with C.P. crumb cup strainer and tail piece, C.P. “P” trap and with integral mounting frame and sound deadening under side with holes to fit faucet above.

The dishwasher only gets hot water.

• CR3321. Elkay Celebrity® Stainless Steel
  33″ x 21-1/4″ x 6-7/8″ Equal Double Bowl Drop-in Sink
• Delta Lenta Chrome Single Handle Pull-down Kitchen Faucet

Laundry

This is the laundry room plumbing plan. The tankless water heater is in the laundry room.

The ladder in the floor is bothering people. This ladder will give access to the loft. It will not be stored in the floor of the laundry room. There are rails in the hallway for it to attach to.

During construction the water lines are tested. The plumbing rough-in pressure test makes sure there are not leaks by putting some pressure on the water lines.

This is the hot water heater. There is a shut-off for the whole cabin in the box with the water heater.

This is the laundry room drain and vent plan.

The construction photo shows where the water lines and vent pipes run.

And here is a photo of the finished laundry room, with the hookups for the washer and dryer.

The bumps on the tops of the pipes are water hammer arrestors.

Bathroom

The bathroom plan has a lot of details.

Shower Cabinet : 32″ x 34″ x 84″ high one piece molded acrylic shower without joints and seams and shall meet ANSI a117.1 and z124.2. unit to be predrilled and shall be provided with towel bar, brass drain with stainless steel strainer, stainless steel curtain roc, factory installed. Provide with Delta no. 1424-lhp pressure balance mixing valve, comply with ANSI / ASME a112.18.1m and ANSI / asse 1016, and 2.1 gpm @ 60 p.s.i. shower head. Shower to be Aquarius no. A3234 or equal.

The bathroom drain plan matches the construction photo below.

All of the plumbing in the house is finished and ready for our plumber to connect to local water and sewer.

Water supply lines shall be CPVC (sch 40 or scrii) or PEX. Water supply lines may be stubbed through the floor (only) with the on-site installation of all lines below the floor to be in accordance with the specifications on this drawing.

The shower is one-piece acrylic. The fixtures are all chrome finished.

The cabin is from Westwood Cabins. You can see more photos and floor plans at www.westwoodcabins.com and www.facebook.com/westwoodcabins.

The rest of the very wordy details on the Code for a Small Pre-Fab Cabin Water, Drain, Waste, Vent and Tankless Water Heater >