Urgent - PVC Shower Pan Pierced By Screws

Posted by Al on October 30, 2005, 9:19 pm

I am having my shower torn out and completely rebuilt.

The trademan who is doing this (and who has done exceptional work for
me in the past) has installed a PVC liner 7 inches up the sides of the
shower and over the curb.

However, when he installed backer board over the PVC liner, he
installed screws into the backer board that were about 1.75 to 2.00
inches above the bottom of the liner where it rests against a sloped
subfloor, piercing the PVC liner at that level behind the backer board.

He intends to lay down a layer of mortar on top of the PVC liner to
create a sloped surface to lay the floor tile on. Thus, the height of
the screw holes (and the punctures in the PVC membrane) will be even
closer to the finished shower floor by the time the tile is installed.

This trademan says that he installed a bead of caulk to prevent the PVC
liner from leaking where the screws penetrated the liner, but I am
still extremely concerned that integrity of the PVC shower pan has been
compromised by the screws that pierce it.

It is my understanding that the PVC membrane should NOT have been
punctured at a point so low to the bottom of the pan.

I would also like to know what would happen if the PVC membrane on top
of the curb is pierced by screws when backer board is installed on top
of the curb. Will this create create a potential for leaks as well?

If screws should not pierce the PVC vinyl membran, what is the
appropriate way to fasten backerboard when a PVC liner has
been installed?

Am I justified in being concerned about the potential for leaks?

Please respond ASAP as the trademan has not installed the tile yet, but
plans on doing so very shortly.

Thank you.

Posted by Edwin Pawlowski on October 30, 2005, 10:20 pm

> However, when he installed backer board over the PVC liner, he
> installed screws into the backer board that were about 1.75 to 2.00
> inches above the bottom of the liner where it rests against a sloped
> subfloor, piercing the PVC liner at that level behind the backer board.

> This trademan says that he installed a bead of caulk to prevent the PVC
> liner from leaking where the screws penetrated the liner, but I am
> still extremely concerned that integrity of the PVC shower pan has been
> compromised by the screws that pierce it.

> I would also like to know what would happen if the PVC membrane on top
> of the curb is pierced by screws when backer board is installed on top
> of the curb. Will this create create a potential for leaks as well?

With the caulk and backer board, it is well sealed. Thee will be tile over
that too right? I don't see any reason for concern. Done right, water
should never get there anyway.

Posted by Al on October 30, 2005, 10:37 pm

The screws piercing the PVC membrane are 1-3/4 to 2" above the PVC
membrane lying on the subfloor, but on top of the PVC liner a sloping
mortar bed will be added as one cannot place tile directly over the PVC
liner.

This means that after the tile on the shower floor is installed, the
screw holes will be much closer to the bottom of the shower floor than
the 1-3/4" to 2" that I listed in my original email.

Sorry for posting my inquiry so often. I had posted it and deleted it
several times - each time revising it a little.

Similar Threads	Posted
Urgent!!! PVC Shower Pan and Screws Piercing the Membrane - Will This Cause Leaks?	October 30, 2005, 8:00 pm
Urgent - PVC Shower Pan Membrane Punctured By Screws - Potential for Leaks - Advice Soliticted Please	October 30, 2005, 9:28 pm
Help with shower leak	June 25, 2006, 7:25 pm
Shower leak	June 29, 2006, 6:39 pm
HELP: Leak behind shower.	September 25, 2006, 3:30 am
Leak in Shower	November 2, 2006, 5:00 pm
Leak from Shower	January 23, 2007, 11:31 am
Big leak from upstairs shower	November 3, 2006, 12:38 am
Help! Hot Water Leak in the Shower!!	February 1, 2008, 11:40 pm
Mysterious Bathtub/shower leak	March 5, 2007, 1:06 pm

Urgent - PVC Shower Pan Pierced By Screws - Will This Cause A Leak?