Swimming Pool Blog
by Rob Cox, May 8, 2012
Many inground pools owners opt to have the attached spa installed at the time of building the pool. Good decision.
Attached spas are fun, even if they're not heated. Small children love their small size and when the kids are asleep, the adults can turn up the heater and enjoy a hot, bubbling spa after dark.
But there is a dark side. Well, not so dark really. Many, if not most attached spas have no problems with the wall that separates the pool and spa - but some do.
This blog post will focus on the Good, but mostly the Bad & Ugly problems that can surface around your pool / spa interface.
Why does Spa Wall Tile fall off?
If your tile is simply falling off, without wall damage behind it, consider yourself lucky. Water will seep into small cracks in the tile grout and freeze during winter. Several years of freeze/thaw cycles will loosen the tile mortar that is holding the tile in place, and gravity will do the rest.
In other cases, more insidious problems are afoot. Spa walls - or the wall that separates the pool and spa, are built with an inside radius, without a capstone or coping stone on top. As your pool expands and contracts with the changing of the seasons, this inside curve is subject to a lot of stress and strain. The pool itself pushes in on the spa wall, very slightly. Over many years of slight pushing, cracks can develop in the wall, mortar and tile itself.
Another reason that the spa wall is weaker than the other parts of the pool is that the spa wall is not up against any earth, like the outside of the pool walls. The spa wall is made with the same steel, gunite and plaster as the rest of the pool, but the gunite is shot in between wood forms. These wood forms can move as the gunite is being added, and this can create voids or pockets that are not as strong as surrounding areas.
My Spa Wall has Cracks in it!
This would be a problem. In the picture shown, the crack has already been enlarged, to remove all the loose material. Typically, the problem will make itself evident to you by smaller cracks, behind tile that has fallen off.
A big hint of an issue is water leaking from the spa wall, into the pool. ;-) Not very common. Usually, you will see only small cracks, or crumbling gunite behind the tile. Evidence.
At the spillway, it's common to see cracking & crumbling at the corners, loosening these spa tiles.
Another type of spa wall failure is when the top of the spa wall breaks off, around 1" from the top, along most of the spa wall. This can be caused by high water levels freezing hard during hard winters, putting pressure on both sides of the spa wall.
My Pool Wall has Cracks in it!
If you have cracks in your pool wall, in other areas of your pool, the cause is different. The top of your pool wall is known as the "Beam" - that area that the pool coping and tile is adhered to. When the expansion joint between the pool and spa is not "true" to the earth, expanding pool decks can push against the coping stones and the Beam of the pool. This will create cracking and crumbling over time.
In each case, it's important to remember - your spa wall is a victim of circumstance. It's not his fault! Your spa wall is doing the job of the Hoover Dam, keeping your pool and spa separated, but the pressures created by an expanding pool wall and pool deck are just too much. Imagine squeezing a soft plastic toothpick between your thumb and forefinger, and you have an idea of the pressures that are exerted on the spa dividing wall.
Fortunately, most cases of spa wall tile repair do not involve damage to any large extent.
How to repair Spa Wall Damage
- Clean up the area. Remove any loose material. Widen the crack with chisels or 4" grinder.
- Cut measured "shorts" of re-bar, and wedge them into various spots in the crack.
- Use thin form wood on both sides of the wall. Connect the two sides with bolts on top.
- Nail the form boards at bottom, right into the pool wall.
- Pour hydraulic cement into the forms and allow to cure. Consult package directions.
- Strip off the forms; remove any rough spots or edges.
How to replace your Spa Wall Tile
- Lower pool water level below the tile.
- Remove any loose grout or rough spots on the base.
- If loose material has fallen out, patch first to bring it up level.
- Moisten the area to be tiled with water.
- Apply a thin layer of Thinset Mortar with a small, notched trowel to a small area.
- Reaffix old tile pieces by hand, or apply new sheets of frost-free pool tile.
- Keep an eye on the tiles to make sure they don't slip. Adjust as needed; disturb as little as possible.
- After 12-24 hours, you can apply a waterproof Tile Grout to the joints between tiles.
- After 3-5 hours, use a scrubber pad and light pressure to clean up the over-grout.