3.1 Introduction

Building means any structure that is used (or intended to be used) for supporting occupancy or sheltering. Building construction is currently one of the largest industries worldwide, i.e., new construction in US was approximately 620 billion US$ [1], and with renovation, maintenance and repair added, the total volume of construction was about 1000 billion US$ (during 1997-1998), corresponding to 12.3% of the GDP. In the EU, the construction market was about 400 billion pounds in size (in 1997) which grows about 2-3% per year [2].

Within building construction, residential construction has the highest share in general (approximately 40%), followed by commercial institutions (30%), public works (20%) and industrial constructions (10%).

There are a number of different materials involved in the building and construction sector, beginning with cement (used to produce concrete) and lumber, which are the classic and common materials. There is also a variety of novel plastics materials being used in the same sector, which are not that old, and their use is ever increasing and replacing the conventional ones. Lumber and composites of various ligno-cellulosic fibres with plastics are being used in large proportions in construction.

Plastics have a wide range of applications in the building industry, and this sector is the second largest user of plastics. These applications range from non-structural to structural uses, inside and outside of the house, because of the fact that plastics materials have several advantages, such as, they are light, economical, durable, have...