drop in tub installation


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Old 09-18-09, 05:29 PM
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drop in tub installation

turns out the new replacement tub is approximately 3/4 inch deeper than old and sits above the retiled deck.

not interested in taking up the new tile and elevating the decking. Plumber suggested using a caulk with sand, friend suggested placing a matching tile quarter round are these reasonable options?
 
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Old 09-18-09, 05:53 PM
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Is this a jaccusi type tub? How many gallons when filled? Was it set on top of wet concrete / grout to support bottom? Was it placed on top of old concrete bed?

CaryMan
 
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Old 09-18-09, 06:14 PM
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CaryMan, appreciate your inquiry. yes it is a Jacusi tub, I removed the concrete on which the original tub was set and plan to set the new tub in concrete so when I do this the flange of the tub will then sit about 3/4 of an inch above the decking. according to the the installation instructions this in itself is not a problem as the decking is not to be the support of the tub but rather the floor and the concrete bed. So it feels like a cosmetic issue.

right now it seems that short of ripping up the new tiles and rebuilding the decking (dont overlook the fact that I am "nosohandy" and well over my buget for this project) i have come up with two options and need to know if they are realistic, or if you or others have some suggestions
 
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Old 09-18-09, 06:43 PM
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Not a problem, just wanted to make sure is was supported properly, that the rim wasn't going to be flexing from all that water. A gallon of water is 8+ lbs.

At best, another layer of rounded over tile will build up about 3/8" and leave 3/8" gap. Thats if it's wall tile thickness. There are tile adhesives that promise to adhere tile to tile. I believe Henry's is one such brand. A 3/8" chaulk gap isn't too bad if applied neatly. Most likely it will require high maintenance because the rim is not sitting tightly and straight down onto the deck with a little bit of force. This is just my personal experience and YMMV.

How specific are the instructions? Any 1-800 number to call? I surmise that when the tub is set on the grout bed it needs to also be tamped down until the rim is sitting squarely onto the deck.

This is my best shot. Hopefully another member will chime in.

CaryMan
 
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Old 09-18-09, 07:15 PM
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If you drop the new tub into place right now does it touch the tile without anything under the bottom of the tub? Generally speaking the only absolute requirement is that the rim not be supporting the tub. You do not need any particular thickness of mortar under the tub, just enough to add support over the entire bottom and to keep the rim slightly (1/16 to 1/8 inch) above the deck.

Can you get to the bottom of the tub from the side after dropping it in place? If so then you can push the mortar into place under the bottom as needed to properly secure the tub. And rather than mortar or concrete (sand) mix you might be able to use a non-shrinking cement-based grout that could be mixed quite thin and "puddled" into place.
 
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Old 09-19-09, 08:32 AM
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I second and third Furd's suggestions.

After additional contemplation, the rim should have a 1/16" to 1/8" gap to the decking. A high quality flexible caulk should be used to seal the deck to the side wall of the rim. Think of the rim as a piston that moves up and down as the sub floor flexes from full tub weight to empty tub weight. The caulk bead must be able to maintain its adhesion to the deck and the side wall of the rim each tub cycle and do this for years.

Get some kitchen counter laminate samples. Two stacked together is 1/16". Let the upper laminate hang over the lower when setting the tub. When the grout is cured, needle nose pliers can grab the upper and slide it out with no damage to the tile deck.

If you absolutely don't have the clearance, you may have to remove the sub floor decking to expose the joists. Cut a "U" shaped recess, sister up the cut joists to increase strength, re-install the decking material, seal the sides, pour your grout, set the tub.

Hopefully it won't come to that.

CaryMan
 
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Old 09-20-09, 06:41 AM
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Furd, CaryMan, DIY projects are both rewarding and challenging. There is nothing like the feeling of finishing but it is the process that makes you wander if you are out of your mind. you both have been very helpful.

Furd, no the rim of the tub does not rest on the decking. Have not yet put in the concret/mortar set. and no I can not get to the underside from the side.

my plan is to shim the bottom to get a simulated position. then I will assess the precisse gap between the rim and the deck. I will then lift out the tub and add the mix replacing the tub. to address the gap My plan than is to insert a 1x2 on the rim of the deck and under the rim of the tub. this wil be tricky. the purpose of this is to give some backing for the caulking so that it does not drop into the hole. recognizing that the weight of the tub is actually being supported by the floor. If the gap is not so geat with the caulking then I will call this good. If on the other hand the gap is visually unappealing I will add the tile quarter round rope tile onto the deck and around the perimeter of the tub. Here I anticipate this will set on a bed of grout.

I will work on this project over the next few days. You will certainly get a report of my success. thanks much
 
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Old 09-20-09, 11:06 AM
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NotSo,

I thought of a trim board to be fitted around the perimeter, but dismissed it cause wood and constant moisture is high maintenance. Also, I did not know how close to a vertical wall the tub would sit.

Cedar is naturally rot resistant. Soft and porous.

Oak would be good, but depending on your geographic location, it could get expensive to do a perimeter.

Popular is tight grained and can be stained dark colors to hide the green hue. A dye may need to be used before the stain coat. Of course, you can paint it with a porch enamel after primer. Enamels can feel sticky to the touch however.

If you go with trim piece, identify where the rim will sit and measure out about 5/8". Strike a line parallel to the outside edge. With tablesaw, cut a 10 to 15 degree slope off. Sort of like a shed roof. Maintain a 5/8" thickness or so at the outside face for it's caulk bead/seal.

Find a good lumber yard that has mill wright capabilities on site and they can do it for you.

An idea to investigate:

2x10 or greater floor joist system at a minimum to even consider.

Will NOT WORK for engineered wood floor joist system without a Structural Engineer.


Identify the mortar footprint needed plus 10% on each perimeter. Determine the depth needed plus 1" mortar bed thickness or less if feasible. Cut out the subfloor deck and notch the joists like a long squared off "U". Sister up the cut joists with another piece of joist material. (Are you over crawl space, unfinished basmnt or 2nd story here?) Glue and screw them together. Add blocking all around and then cut and reinstall the original subfloor decking. (Don't forget it's thickness when notching) Pour the non-shrinking grout loose enough to be tamped down and out of the way from inside the tub. A carpet lined 2x4 and a heavy duty rubber mallet would most likely suffice and would not damage the tub bottom.

Please take this advice and verify. There are rules of thumb to how much of a joist member you can cut away and where. The optimal configuration is if the floor joists are running perpendicular to the tub's long length. This means less linear length of joist material is compromised and is spread over more joists.

Copy this post's link location and ask in the Carpentry and Remodeling Forum here. Take some pictures and upload.


CaryMan

P.S. Be sure that lowering will not negatively affect your plumbing and electrical hook-ups.

P.P.S. I cannot possibly know all your parameters from this location. I can only speak in generalities.
 
  #9  
Old 09-21-09, 08:20 AM
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Some other considerations.

The tub deck must be waterproofed, and the tub must be sealed to the tub deck such that it is completely watertight. If you decide to use another layer of tile as a filler under the tub flange, don't use a tile adhesive (also called mastic), use a good quality modified thinset to bond the tile to the tile. Mastic can reimulsify if it gets wet. You may have to abraid the tile below to get a good bond. You must use caulk, not grout at the old tile to new tile joint, as it must be waterproof (grout is not waterproof). You must also use caulk where the new tile will meet the tub flange. The key is to make sure that you have the tub to deck connection 100% waterproof.

While the deck is generally not what supports the weight of the tub, its used as a guide when setting the tub, as to level and mortar height needed underneath the tub. You'll want to put some thick temporary shims under the flange to make sure the tub is set level and you have adequate cement thickness and coverage for support from below.

I now you don't want to hear this, but your best bet would be to rebuild what you have so that the deck is the proper height.

Have you dry fitted the tub yet? Do you know exactly how much height issue you are dealing with? What is the height of the finished deck, and what is the height that it should be according to the installation instructions?
 
 

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