So far we have only approached two sections of the coping where the stones were most loose, as a complete tear out and redo would be too intensive and disruptive all at once. Perhaps we may get to tackling the rest of the stones eventually.
In my previous post, I presented the idea of adhering a sheet membrane (intended for tile installations) over the exposed steel of the uncovered wall sections. We decided to try this method using Schluter's KERDI fabric membrane and KERDI-FIX adhesive. Although more expensive than many alternative and sometimes better products, Schluter is easy to source.
Procedure
There are some details and learned lessons omitted from the above guidelines to keep them generalized. These mostly pertain to the stone installation procedure over our plastic stairs where the membrane approach was not used - I will detail this by adding it later.
In my previous post, I presented the idea of adhering a sheet membrane (intended for tile installations) over the exposed steel of the uncovered wall sections. We decided to try this method using Schluter's KERDI fabric membrane and KERDI-FIX adhesive. Although more expensive than many alternative and sometimes better products, Schluter is easy to source.
Procedure
- Remove loose stones and chisel/scrape off mortar and any loose material. For extra measure, I cleaned our stones with diluted liquid chlorine followed by pressure washing.
- Remove mortar bed and diamond lath from top of steel walls and the concrete collar/bond beam. A hammer drill with chisel bits works well for this.
- Remove screws from the steel walls (if applicable) and clean any loose material and surface dirt/rust. We used a light pass of the angle grinder with a wire wheel and a flap disc.
- Cut strips of sheet membrane to rough size before application for convenience - check pictures for reference.
- Width of each strip should be slightly wider than the top flange of the steel wall as it can be trimmed after installation
- Length will depend on the shape of the pool - a curved edge will require shorter pieces than a straight one. Longer pieces will be more difficult to work with, so it is better to work in manageable sections.
- Apply adhesive to the top flange of the steel wall (avoid covering liner track) and spread until even with a small v notch trowel. Apply more adhesive if there are any bare spots. To accelerate curing, water can be misted onto the adhesive with a spray bottle.
- Place and firmly embed the sheet membrane into the adhesive, taking care to minimize bumps or adhesive buildup. A drywall or putty knife can be used.
- Subsequent sections can overlap with previous ones, but it is not necessary and perhaps is best avoided. Personal experience and various internet sources have shown that a KERDI to KERDI connection with KERDI-FIX does not form a strong bond.
- Comparable products will probably exhibit the same result.
- Let cure as specified by the adhesive and then trim the membrane to its final shape. Result should be a membrane that fully covers the exposed steel and has no loose edges lifting from the substrate
- Install stones with a suitable mortar. Mortar selection will depend on various factors. We used CBP's Megalite, a lightweight heavily modified non sag mortar that can be used up to 3/4" thick.
- Fill joints between coping stones. Once again, selection depends on various existing conditions. (Have not done this step yet)
- If Type S or N mortar was used to install the stones, it can also be used to fill in the joints.
There are some details and learned lessons omitted from the above guidelines to keep them generalized. These mostly pertain to the stone installation procedure over our plastic stairs where the membrane approach was not used - I will detail this by adding it later.
