The Uxbridge College Case Study on how a floor finish can fail

April 2011

The project to screed the new sports hall and changing area at Uxbridge College using FlexiDry F2/14 day dry was handed over to a screeding contractor on behalf of the Principal Contractor.
At the end of a 13 day waiting period, the screed contractor conducted the moisture tests on the area of the sports hall that was screeded the last, and it was found that the screed had higher levels of moisture than expected. Though this was a premature test for a screed with a specified 14 day drying time, the Principal Contractor who was under pressure to come up with a quick solution for the problem made the hasty decision of going for the application of DPM on the 650 sm area. Consequently, a minor error from the part of the screed contractor in judging the right time for the moisture test resulted in an inappropriate decision which in turn caused the client to incur substantial additional expenditure.
In the changing area, the vinyl floor finish was noticed to have a moisture problem. The vinyl finish was found to have bubbled and lifted. In order to examine the substrate, the vinyl was removed and it was found that the adhesive had become moist and turned milky. As a result a Tramex moisture test was later carried out in the presence of the Screed Manufacturer, the Principal Contractor, Floor Screeding Contractor, and the Floor Finishing Contractor, and it was found that the screed was a CM 1.6% and the latex 3%, and the adhesive was considerably wet.
It was found that the screed was dry. But the problem could have arisen due to anything from the application of vinyl when the latex compound had been still wet, problems with the adhesive or penetration of water into the vinyl or seepage of water into the screed during construction. However, the real root of the problem could not be diagnosed due to the negligence from the floor finishing contractor’s part in ensuring that the screed was tested before applying the vinyl finish to the latex coat.


It should be ensured that the right method of moisture testing is followed and recorded strictly before the final floor finish is applied, to avoid such failures in the future.