Flexing tub may ruin bath caulk

Q: We are the original occupants of a condominium built in 1994. The bathtub is enamel-covered steel, surrounded by tile. The problem is how to fill the 1/8th inch gap between the tile and the tub. My husband believes that during construction the drywall and tile were not brought down far enough to be effectively sealed. The original caulk began to fall off soon after we moved in. He's tried filling the gap with "tub caulk," but it too eventually falls out. So every time we shower there is water running into the gap and behind the wall, probably doing a lot of damage we cannot see.

A: All tubs built in the last 50 years or so and used for showers, too, have a lip around the three waterproofed sides called a flange. This flange is about an inch tall in most cases and should prevent water from absorbing into the wall where the caulking along the bottom of the tile has failed. A one-eighth-inch gap between the tile and tub is not excessive and is in fact desirable.

Caulking along the tub top is overrated and mostly for cosmetic purposes. The reasons the caulking is failing with such regularity could be that the caulking was applied wet and did not set, was applied to a wet area and did not adhere, or the tub itself is flexing.

Reasons for flexing include manufacturing defects such as loose or broken corner stiffeners that allow the tub to flex when filled with water. Or, a more likely scenario is that the tub was installed slightly askew, is not resting squarely on the floor, or is not attached tightly to the studs behind the flange.

Check to see if the tub is tight by stepping along the upper rim and at all corners. There should be little to no movement. If it flexes or moves at one area, it was not installed right. Next fill the tub completely with water. If the eighth-inch gap expands greatly, you have a structural flaw.

Try a butyl or siliconized caulking. These types will give you a bit more stretch than a straight latex bath caulking. Apply your new caulk only after filling the tub completely, making sure all targeted surfaces are dry, including the bottom lip of the tile and the substrate drywall/cement board.

As an aside, most new fiberglass shower bases have "weepholes" built into the outer corners that allow water to run back into the shower to be drained away. The reason the water gets into this area is not from lack of caulking along the bottom, but from lack of caulking at higher areas and from saturated, unsealed grout that has allowed moisture to penetrate.

Q: If I want to come forward and admit that work was done to my home without a needed permit what is the penalty structure within the Seattle city limits?

A: Alan Justad, spokesperson for Seattle's Department of Design, Construction and Land Use says that work done without a permit generally is treated like a new application.

One common and important issue is whether the work meets the Land Use Code. Was an addition added within a required setback and does it meet various other requirements? If a variance is needed, they are based on property-related hardships, not the fact that the work is already completed.

Inspectors will need to confirm that the construction was done correctly. Justad asks rhetorically, "was the foundation excavated and poured correctly, beam sizing adequate, plumbing and wiring done to code and so forth?" Some opening up should be expected.

Consultants such as an engineer may be required in some cases. You would be fined if you refused to make the changes needed to meet the codes. Justad added that if it's clear that the work was done years ago, less stringent standards apply, with safety the ultimate barometer.

Q: When reroofing, is it necessary to install continuous sheathing if none is present? I was under the impression that continuous sheathing was required for earthquake reasons. I recently saw a shake roof replaced. I understand that it is better for shakes if they are on skip sheathing rather than continuous sheathing, but I was still very surprised to be able to see daylight through the sheathing (in areas that had not yet been covered with roofing felt).

Reroofing permits are not required in Seattle, nor is solid sheathing required on a reroof. However, if the sheathing is replaced, it will require a permit, as this is considered a structural modification that must be brought up to modern code. DCLU's Alan Justad said, "It's the philosophy of `you touch it, you fix it'."

Ask The Expert answers readers' questions every Saturday. Send questions to Ask The Expert, Seattle Times, P.O. Box 70, Seattle, WA 98111, or call 206-464-8514 to leave your questions on Ask The Expert's recorded line. E-mail address is dhay@seattletimes.com.

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