I feel somewhat comfortable with my ideas for the DWV system. I'm planning to temporarily use 2 AAVs to avoid having to cut through the exterior wall. Although, one will actually be in the kitchen under the sink because that S-trap is just aggravating. The other AAV will be for the lav and toilet. Toilet vent will come up and merge with lav vent & have an AAV (which will be hidden but still have airflow and be accessible). I'm still quibbling with myself on the exact placement of the pipe with the AAV.
For the washing machine, I'm going to run the trap arm behind the washer and then have a vent go up just after it gets out from behind the dryer, it will go up to about 6" above the top of the standpipe and then run horizontal to tie in to the main vent stack. Although, technically, if it is less than 8', I might be able to get away with just running the trap arm to the main vent stack. Due to the positioning of the main vent, I will probably have to run the trap arm for the tub/shower west a bit and then have the vent come up and have an elbow to run back to meet with the main vent.
I have a diagram of the parts I think I will need (any suggestions of modifications are welcome). I based it on what parts I could actually find for sale & I may change my mind again. I want to have the most efficient use of parts. I should have specified that all of the cleanouts will be 3". (Do I need any cleanouts in different spots?)
When I did my water supply diagram, I forgot about the old washing machine water lines. Instead of moving the shower lines, I might be able to eliminate the shower lines & just divert the washing machine lines over since it might be a shorter distance.
Since some of the lines will be moved closer to the edge of the house, they will be more vulnerable to cold. I will wrap them in insulation and I'm thinking of getting those cheap foil insulation blankets that they sell in the camping section and putting some up near the skirting and covering the skirtless part to keep warmer air in and colder air out. For the skirtless part, it can be moved aside if we need to climb under to access it.
I don't want a repeat of the pipes bursting again. Also, because PVC is no longer allowed above ground and all of my cold water supply lines are currently PVC, I am thinking of transitioning to PEX. I have 3/4" PVC & CPVC so I'm thinking of going with 3/4" PEX. I'm currently looking in to the options and trying to decide between PEX-A and PEX-B. I'm also trying to decide on fittings. The crimping tools look expensive and I don't know if I have the hand strength to use them (unless they've made them easier to use than shown in some of the youtube videos). I'm also concerned that if I try to use expansion fittings that my lack of coordination may lead to just ruining the ends of the PEX by overstretching or not being able to get it to go over, but I haven't ruled it out. Even though it will reduce the inside diameter a bit at some parts that merge, I'm thinking of using the sharkbite fittings.
1. Which is more secure? Sharkbite (push-fit) or Expansion?
2. Do I need check valves on my water supply lines for the washing machine?
3. Can I have a check valve on the toilet water supply line?
4. Where would check valves be installed and do they need to be accessible?
5. Can I run PEX from the shower valve to the tub spout? (I plan to get an IPS valve rather than a CC one)
6. For the IPS valve, what sort of bonding material do I need to use on threaded connections? (pipe dope?)
7. How hard is it to convert from a 2 handle shower system to one handle pressure balancing/temp control system?
8. Can I use the existing metal piping from the old shower and use some sort of couplings to link the metal to PEX to go from the showerhead to the moentrol valve?