Page 26 - Parquet International december 2014

ON FIELD
IN DEPTH ANALYSIS
Sometimes, they return... Concrete laying surfaces: years go by but the problems remain the same.
Here are two examples of how NOT to do things
There are days in which I really fail to understand why - even after more than two decades of seminars, meetings, and more than ample technical presentation – I keep encountering the same problems again and again. Many people working in the construction business, who in my opin- ion are often unprepared, resolutely contin- ue making the same mistakes, even if the correct technical information is copious and has been widely diffused throughout the na- tion: just consider how much money the leaders in the sector have invested in re- search and the distribution of technical doc- umentation, videos, and brochures. As the Latin poets were fond of saying, persever- ance in error is diabolic, but when faced with certain problems, the entire body of techni- cal knowledge seems to be no use at all to these people. Below, I describe situations that I examined in two different work en- vironments in two geographically distant in
which the final result was practically the same. In both cases, fortunately, the
MAURO ERRICO
parquet installer assigned to the job proved to be sufficiently scrupulous, and raised his objections regarding the quality of the lay- ing surface right from the start. These par- quet installers were undoubtedly dismissed as “fanatics”– as usual – but the final client forced to suffer the initial inconvenience, proved capable of solving the problem with- out increasing the damage. Let’s take a clos- er look at both cases in question.
The first case: analyzing
the screeds prior to laying
My first technical inspection regarded the structures of a few self-leveling concrete screeds laid in a number of apartments for a total 600 m2 surface area at a new building construction site.
Screed examination overview
I analyzed the rapid hardening self-leveling screeds, which consisted of a floor slab and embedded underfloor heating systems. Around four months had passed from the fi- nal casting of the screeds by the time I ar-
rived. The Director of Works had in- formed me that their thickness varied from a minimum 3 to a maximum 8 cm. Measurements had been taken starting from points just over the
heating systems.
Metal reinforcement webbing – with-
out expansion joints – had been embedded inside the screed, especially near the “doors”, which are usually the areas of the room with the greatest variations in dimensions. For this type of screed, the surface area that should ideally be covered without interruption is usually around 40 square me- ters, and so-called expansion joints are always created near door thresholds. My first visual inspection re- vealed the following anom- alies in all the apartments
with screeds already laid:
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