mixing valve installation

[JCA1]

I will be installing our shower/tub mixing valves soon. I will be using the thin wall installation method for the valve. Do you put plumbers putty or silicone around the echrusion( sorry for the misspelling) plate? How about the back side of the tub spout?

[LazyPup]

When installing your shower mixer there are a number of things you should be aware of:

Most shower mixers have 1/2 FIP (Female Iron Pipe) connections on the mixer body and you must use a MIP (Male Iron Pipe) adapter to connect the water lines.

Due to the high risk of damaging internal parts in the mixer I prefer not to solder copper while attached to a mixer body. Instead, I prefer to pre-asseble the male thread adapters on the water line risers and the shower head standpipe, then make a final connection at a point away from the mixer body. Example, precut and dry fit the shower head riser to make sure you have the correct length of pipe, then solder the male thread fitting on the bottom end. After the solder is cool to the touch you can then apply some pipe dope to the threads and screw the riser into the mixer body. Once you have the pipe tightened into the mixer body you can then spring the top end of the pipe away from the wall a bit to solder the Drop ear elbow on top for the shower arm.

When installing a mixer in a bathroom on an upper floor where the water lines are coming in from the floor below I like to make the risers from the floor below, solder the male thread adapters on the end then when cool apply pipe dope and tighten the risers into the mixer body. Then make the final connection at the junction of the water line below.

When it is necessary to make a solder joint in the risers near the mixer I like to remove the mixer cartridge and try to make the solder joint at at least 12" away from the mixer body. I also wrap a wet rag around the mixer body and top end of the pipe to protect it from heat.

Great care must be taken when installing the blocking to insure you have the mixer body set at the correct depth from the finished wall.

When installing the spout I prefer to use 3 wraps of RED TEFLON tape on the male thread adapter before applying the spout. I also use the RED TEFLON on the shower arm before screwing it into the riser.

NOTE: WE use the pipe dope on the fittings on the mixer because they are permanent fittings in a concealed space and therefore we don't need to anticipate them being removed. Spouts on the otherhand have a tendency to corrode and require changing, therefore I use TEFLON to insure they will be fairly easy to get off at a later date if necessary.

Absolutely do not apply plumbers putty to the excutcheons or spout. Whether or not to use silicone is a matter of preference. I prefer to apply a light film of clear silicone to the Escutcheons, but do not apply it to the spout. Most spouts have a weep hole on the underside of the spout body to permit any water that may leak inside the spout to drain out the weep hole and down to the tub rather than going inside the wall. Applying silicone to a spout would defeat the weep hole.