Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

 
 
or
Submit
Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 4/26/2017

what type piping is good for Washington State Hot water ? Pex or CPVC or Copper since in will be under crawlspace

I live in Washington State and just bought house with no insulation under crawlspace water always come out cold even in the Summer time ! just want to take my time to learn how to do the change out the Water heater pipe under crawlspace !
thanks

Do you have the same question? Follow this Question


2 Answers

0
Votes

My personal opinion - never Pex unless forced into it because of inaccessibility to run rigid pipe (and even then I would prefer flex modified VC tubing) - just too much continuing quality and connection design problems with Pex. Some Pex behaves well if frozen, I have also seen a number of products which split very readily when frozen - my go to plumbing company does not like it for thsat reason and because of the continuing quality control and breaking-off connection issues.


CPVC is brittle when cold (and even when not) but is easy to run in a crawlspace and not terrific if it freezes - the cold brittleness makes it split easier than PVC or copper. Would be my second choice normally. Copper is expensive now, but lasts a long time unless you have pretty corrosive or high-mineral hardness water, and is pretty resistant to freezing (not that you should run your pipes where they will ever freeze). Would be my choice for normal cases, but ask around about corrosivity of your water, because some areas in WA (especially the glaciated areas, which is a lot of the state) have moderately to occasionally highly corrosive waters, and a lot of the eastern and volcanic part of the state has corrosive and/or high mineral content water too. If you use copper I would use the thickwall type K, not the normal type L or the thinwall series M pipe if there is any chancer of freezing - worth the extra not too many bucks for your presumably 50-100 feet of run, in my opinion. Of course cold pipes can be wrapped with pipe wrap closed cell foam insulation. One mistake a lot of people make, assuming the hot and cold pipes run next to each other, is using foam pipe wrap on the pipes themselves. This does a fair job of making them warmer in cold weather but does not stop them from cooling all the way down overnight, and the foam insulation protects them from the radiated heet coming from the floor above which can make the difference between freezing and non-freeing, and may actually cause cold pipe freezing because it may have been OK with the radiated heat from the hot pipe warming the run area but the pipe wrap on the hot pipe is now largely blocked off by the pipe wrap, reducing the temperature in the run area. Avoid doing anything that makes maintenance access a pain, but if your crawlspace water pipes run cold, if you insulate across the underside of the joist spaces (longitudinal or in segment crosswise with wood or foam board blocking to isolate the pipes, as applicable), then those joist bays become a warmer utilidor - or utility run. Simplest way to do that is fiberglass unfaced insulation batt set below the pipes only, in the lower part of the joist bay, using lath or a stapled-on netting to holdthe batts in. Thickness dependent on the clearance from bottom of joist to the pipes - R-13 (3-1/2" thick) is usually what fits, sometimes R-21/R-22 with deep joists or some engineered wood trusses. More effective but harder to access, where exposed foamboard is legal in crawlspaces, is insulation in the joist bay (can be just under pipe, or at sides too along the joists, but you want an open space around the pipes and hot and cold in same open space) - then rigid foam board on the underside of the joists, put on so it comes off easy - using headless nails or streaker screws for instance, and only enough to hold it in place. Note exposed foam board is a bad idea in termite infestation areas - they like to tunnel and build their freeways and nests in it. However, batt insulation is a bad idea in wet crawlspaces due to moisture absorption and mold growth too, so both have drawbacks. Sometimes, in colder areas, a vapor barrier is put over the bottom for moisture and insect control, but that does risk condensation at the vapor barrier from household moisture going through the floor in the winter, so generally vapor barriers on the bottom of the joists is not recommended in cold climates over cold airspaces. I do emphatically recommend against spraying the pipes with foam-in-a-can, not only because that will block the heat from the overlying floor, but alsoany plumber working on the pipes in the future will not only curse you but may well set your house on fire when soldering if using copper pipe. Depending on how long your runs are and how cold the hot water comes out, it is possible to put in a recirculating loop on the hot piping (and cold too to prevent freezing in some instances) - continuously pumping (with very low horsepower pump) through a loop so there is hot water at each faucet/drawpoint all the time - though of course this does make the pipes in the crawlspace warmer so you lose more energy there (especially if not insulated) so you have to balance your wants and needs. But recirculation (especially with long hot water runs like in long ranch or U-shaped houses) can effectively solve the problem of it taking a long time for the hot water to actually run more than luke warm. If that is an issue, now would be the time to install a loop system.

Answered 1 year ago by LCD

0
Votes

ARgggggh - Angies List computer is compressing and removing paragraph breaks again - will divide paragraphs by this to try to make it readable - ignore the first response above

nnn

nnn

===============

My personal opinion - never Pex unless forced into it because of inaccessibility to run rigid pipe (and even then I would prefer flex modified VC tubing) - just too much continuing quality and connection design problems with Pex. Some Pex behaves well if frozen, I have also seen a number of products which split very readily when frozen - my go to plumbing company does not like it for thsat reason and because of the continuing quality control and breaking-off connection issues.

nnn

nnn


CPVC is brittle when cold (and even when not) but is easy to run in a crawlspace and not terrific if it freezes - the cold brittleness makes it split easier than PVC or copper. Would be my second choice normally.

nnn

nnn

Copper is expensive now, but lasts a long time unless you have pretty corrosive or high-mineral hardness water, and is pretty resistant to freezing (not that you should run your pipes where they will ever freeze). Would be my choice for normal cases, but ask around about corrosivity of your water, because some areas in WA (especially the glaciated areas, which is a lot of the state) have moderately to occasionally highly corrosive waters, and a lot of the eastern and volcanic part of the state has corrosive and/or high mineral content water too. If you use copper I would use the thickwall type K, not the normal type L or the thinwall series M pipe if there is any chancer of freezing - worth the extra not too many bucks for your presumably 50-100 feet of run, in my opinion.

nnn

nnn

Of course cold pipes can be wrapped with pipe wrap closed cell foam insulation. One mistake a lot of people make, assuming the hot and cold pipes run next to each other, is using foam pipe wrap on the pipes themselves. This does a fair job of making them warmer in cold weather but does not stop them from cooling all the way down overnight, and the foam insulation protects them from the radiated heet coming from the floor above which can make the difference between freezing and non-freeing, and may actually cause cold pipe freezing because it may have been OK with the radiated heat from the hot pipe warming the run area but the pipe wrap on the hot pipe is now largely blocked off by the pipe wrap, reducing the temperature in the run area.

nnn

nnn

Avoid doing anything that makes maintenance access a pain, but if your crawlspace water pipes run cold, if you insulate across the underside of the joist spaces (longitudinal or in segment crosswise with wood or foam board blocking to isolate the pipes, as applicable), then those joist bays become a warmer utilidor - or utility run. Simplest way to do that is fiberglass unfaced insulation batt set below the pipes only, in the lower part of the joist bay, using lath or a stapled-on netting to holdthe batts in. Thickness dependent on the clearance from bottom of joist to the pipes - R-13 (3-1/2" thick) is usually what fits, sometimes R-21/R-22 with deep joists or some engineered wood trusses.

nnn

nnn

More effective but harder to access, where exposed foamboard is legal in crawlspaces, is insulation in the joist bay (can be just under pipe, or at sides too along the joists, but you want an open space around the pipes and hot and cold in same open space) - then rigid foam board on the underside of the joists, put on so it comes off easy - using headless nails or streaker screws for instance, and only enough to hold it in place.

nnn

nnn

Note exposed foam board is a bad idea in termite infestation areas - they like to tunnel and build their freeways and nests in it. However, batt insulation is a bad idea in wet crawlspaces due to moisture absorption and mold growth too, so both have drawbacks. Sometimes, in colder areas, a vapor barrier is put over the bottom for moisture and insect control, but that does risk condensation at the vapor barrier from household moisture going through the floor in the winter, so generally vapor barriers on the bottom of the joists is not recommended in cold climates over cold airspaces.

nnn

nnn

I do emphatically recommend against spraying the pipes with foam-in-a-can, not only because that will block the heat from the overlying floor, but alsoany plumber working on the pipes in the future will not only curse you but may well set your house on fire when soldering if using copper pipe.

nnn

nnn

Depending on how long your runs are and how cold the hot water comes out, it is possible to put in a recirculating loop on the hot piping (and cold too to prevent freezing in some instances) - continuously pumping (with very low horsepower pump) through a loop so there is hot water at each faucet/drawpoint all the time - though of course this does make the pipes in the crawlspace warmer so you lose more energy there (especially if not insulated) so you have to balance your wants and needs. But recirculation (especially with long hot water runs like in long ranch or U-shaped houses) can effectively solve the problem of it taking a long time for the hot water to actually run more than luke warm. If that is an issue, now would be the time to install a loop system.

Answered 1 year ago by LCD




Related Questions


Terms Of Use
|
Privacy Policy