Waterproofing a shower

[NYC-DIY]

Would like to get a few opinions. My contractor is building the shower with the following layers..

Floor:

- plywood
- no pre-slope
- 40 mil PVC liner
- traditional drain
- sloped mud bed
- laticrete
- thinset & tile

Curb:

- wood
- same 40mil PVC from floor
- concrete board
- laticrete
- thinset & tile

Walls:

- studs
- concrete board
- laticrete (I insisted in this. He claims it is not needed on shower walls and he's never had a shower fail)
- thinset & tile

Would like several opinions on what is good and bad with the above since it is weird mix of traditional and topical waterproofing. Specifically:

1. How bad to have no pre-slope considering pan with laticrete also?
2. Is is ok to have both PVC liner and laticrete?
3. Ok to build curb with laticrete over concrete board?
4. What are concrete board seams (curb and wall) sealed with as I may have to tell them?
5. Is the laticrete necessary on walls like I insisted or would a wall with only concrete board and thinset&tile been ok like my contractor said?

Thanks!

[johnfrwhipple]

Would like to get a few opinions. My contractor is building the shower with the following layers..

Floor:

- plywood
- no pre-slope
- 40 mil PVC liner
- traditional drain
- sloped mud bed
- laticrete
- thinset & tile

Is your contractor going to use the "Divot Method" of shower base construction? You say Laticrete - do you mean Laticrete's Hydro Ban?

Curb:

- wood
- same 40mil PVC from floor
- concrete board
- laticrete
- thinset & tile

Wood has no business in a shower's curb construction. Make one from bricks or concrete! Laticrete = Hydro Ban???

Walls:

- studs
- concrete board
- laticrete (I insisted in this. He claims it is not needed on shower walls and he's never had a shower fail)
- thinset & tile

Your missing the building paper or poly if he goes this route. I would want the back side and bottom of the concrete board Hydro Banned if the board is to be placed into the shower's mortar bed.

Would like several opinions on what is good and bad with the above since it is weird mix of traditional and topical waterproofing. Specifically:

1. How bad to have no pre-slope considering pan with laticrete also?

Horrible if no divot method is being used. O.K. if the PVC liner is used as a back up to the Hydro Ban system. If you are going with Hydro Ban on the floor why not use there new drain? It's like a KErdi drain but made by Laticrete.

Or you could use a Noble Company Noble Flex Flashing and then Hydro Ban - better get permission first! I've used this system on many showers with great success.

2. Is is ok to have both PVC liner and laticrete?

Of course. Laticrete endorses this very technic in their steam shower specification. Check it out. It is a good guide to follow. http://www.laticrete.com/portals/0/tds/tds172.pdf

3. Ok to build curb with laticrete over concrete board?

I would use Laticrete 3701 with expanded diamond lath. 2" thickness required on floor and I would do the same on the curb top. You would be better off with a brick curb or concrete curb.


4. What are concrete board seams (curb and wall) sealed with as I may have to tell them?

They should be first taped and thin-setted first. This needs to dry. The 3701 Laticrete deck mud will need at least three days to cure before waterproofing.
Make sure you tell your crew to flood test the shower pan! All water should drain away after the test.


5. Is the laticrete necessary on walls like I insisted or would a wall with only concrete board and thinset&tile been ok like my contractor said?

Necessary - no. Should it be there yes. By code it's not required.

Careful hiring an old timer and making him use new products. Find out the schedule. Ask what products will be used and ensure the right process is used.

The shower should be build and then allowed to dry - three days.

Then the waterproofing process - 2-3 days.

Flood test 15minutes to 72 hours. 3 days is best.

Then tile work 2-3 days.

Then wait a good week.

Then grout.

Then wait a good week.

Then seal the grout.

Do you have time for this? If not then you need to use a different approach or drop your standard.

You can't mix and match approaches and everything needs proper cure times.


It is a tough business to build a shower right. A proper build comes with many part days or half work days. This is why we only do shower waterproofing here in Vancouver - this way we can bounce around and keep our clients projects moving forward. A typical shower crew would prefer to start and finish your job Monday to Friday. This is best for them - not you. Skipping a flood test is best for them - not you. Grouting after the tile is done is quick and requires no trip back - not the best for your tile assembly.



Thanks!

Good luck with the renovation - DO YOUR HOMEWORK!

Did you check references of this crew?

JW

[jadnashua]

The liner flat on the floor should be a major red flag...plumbing code requires the waterproof layer to be sloped to the drain. WHEN, not if, moisture makes it beneath the setting bed, it must have a path to the drain, and if it is flat, it will NOT flow to the drain and will slightly accumulate. The chemistry of mortar is that after a couple of years, the pH changes and it then starts to smell like a swamp if it is used a lot and not given a chance to thoroughly dry out.

Insist it is built per one of the approved methods which ALL require the liner to be on a sloped bed.