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DROP-IN TUB INSTALLATION

AM's picture

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Anybody had experience with installing cast-iron drop-in tubs.Do you set the tub in place on a mortar bed for support and then build the deck around it, or do you build the deck first and lower the tub into the opening (very carefully!!)?

(post #170660, reply #1 of 7)

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Build the frame and deck for the tub first. When you're ready to drop the tub in, put the bedding material in first - make it thicker than the distance between the tub and the floor. Cover the bedding mortar with some plastic sheeting so it doesn't stick to the tub bottom. Then while the bedding material is still soft, drop the tub in place so it molds to the bottom of the tub.

(post #170660, reply #2 of 7)

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Why is bedding mortar necessary? It couldn't be used on an open joist floor. I recently bought an Americast drop-in to replace an existing corner tub, and all that was needed was a ledger board on the back edge. It supported itself, otherwise.

(post #170660, reply #3 of 7)

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Yes, cast iron will support itself, if properly supported from the upper flange or from below with plywood. The problem is that you can not build the bottom dimension exactly. So one builds it an inch or so higher, and fills up the void with mortar. It could be overkill. Hey for $5 worth of mortar, what do you have to lose?

Bob Martin

(post #170660, reply #6 of 7)

bump

 

 

(post #170660, reply #7 of 7)

the way they do it here is to build the frame, set the tub, hook the plumbing drains, and then pour super wet mortar under tub letting it flow.

(post #170660, reply #4 of 7)

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Anybody had experience with installing cast-iron drop-in tubs.Do you set the tub in place on a mortar bed for support and then build the deck around it, or do you build the deck first and lower the tub into the opening (very carefully!!)?

(post #170660, reply #5 of 7)

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Sorry to disagree, but I have seen tubs sag and then completely drop through the opening. It is much better to support the unit from the floor than to hang it from some OSB or flimsy frame. Think about it, the floor is engineered, the frame is not. How much does one of those babies wiegh, with water and a person in it? What if it only shifts a fraction of an inch. Will that PVC plumbing stand up to that?