In this issue, Phil Nightingale provides a fast-track solution for refurbishing flooded school halls.
Following storms last year, we were called to a school where the roofs of the two school halls had been blown off by the wind. Consequently, they were flooded and the floors needed replacing. When I got there, water was cascading in.
Once the roof had been repaired, a solution was needed to refurbish the floors as quickly as possible so that the facilities could be returned to use.
First look
The floorcoverings in both school halls were wood, so they had begun to warp and were completely ruined; in one there were wooden blocks, installed in a herringbone pattern; in the other there was a wooden sprung sports floor.
When the floorcoverings were removed, it was evident that the sand/cement screeds underneath weren’t in a good shape. Rather than being strong and compact, they were crumbling and yellow. When some of the wood blocks were lifted, parts of the floor came with them. The screeds were probably past their natural life span, but undoubtably the moisture had worsened the problem. Unfortunately, this meant that they would need replacing before new floorcoverings could be installed.
Fast-track solutions
To speed up this process, concrete flowing screeds, which cure overnight and can be pump-applied, were installed to replace the base.
Normally, you would have to wait weeks for a newly installed concrete screed to dry sufficiently to install floorcoverings without risking floor failure. Where subfloor relative humidity levels exceed 75% (or 65% where wood floorcoverings will be installed), there is the potential for subfloor moisture to attack floorcoverings and adhesives, potentially resulting in complete floor failure.
However, in situations where a fast-track solution is required, instead of waiting for the subfloor to dry naturally, a moisture management solution can be deployed to suppress excess subfloor moisture.
In this case, F. Ball’s Stopgap F78 waterproof surface membrane was used. The solvent-free, one-component, ready-to-use system requires two coats to create a barrier against RH values of up to 95%. The first coat requires 15-20 minutes curing time; the second requires a further 30 minutes to cure, meaning a barrier against residual construction moisture and rising damp can be created in less than two hours.
Heavy-duty base
When using Stopgap F78, you don’t need to prime the surface prior to the application of other subfloor preparation products, so flooring contractors could proceed straight to applying a suitable levelling compound to create a perfectly smooth base for the receipt of new floorcoverings once the waterproof surface membrane had cured.
F. Ball’s Stopgap 300 HD heavy-duty levelling compound was chosen for its high compressive strength, meaning that floors will be able to withstand the high levels of wear that the school halls were expected to be subject to, as well as its excellent self-levelling properties, reducing the likelihood of imperfections showing through thin vinyl floorcoverings.
Helpfully, the levelling compound can also be pump-applied up to 1500m2 per day, dependent upon manpower, thickness applied and equipment used, saving further time.
Final thoughts
Once the levelling compound had cured, flooring contractors were able to install new wood-effect cushioned vinyl sheet floorcoverings. To do this they used F. Ball’s Styccobond F46 pressure sensitive adhesive. The strong initial tack it provides is useful for holding floorcoverings in place when working with both vinyl sheet and tiles.
Thanks to high-performance products, we were able to turn around what was a real nightmare situation quickly.
Phil Nightingale is F. Ball technical representative for the East Midlands.
F. Ball’s regional technical representatives provide advice to flooring contractors on how to get the most out of F. Ball products, including conducting site visits and producing case-specific reports advising on the best course of action for particular flooring projects. Find out who your technical representative is here.