Furan Resin Membranes

Figure 45-8 in a modern food piant, a properiy designed and laid floor tile (8 in. x 3 / in. X 1 /i6 in.) floor, using a A in. thick glass cloth-reinforced hot asphalt membrane and a furan resin bed and grout. Note the flexibilized epoxy expansion joint. 

On another contract, in this case the principal was a university, all the inspection was to be handled by the general contractor, including that of the laying of "dairy brick" pavers. The specification was absolutely clear, including a requirement that the brick be laid in a furan resin bed a minimum of Vg in. thick, placed over a hot asphalt membrane. The finished floor was to have no greater variation in elevation between adjacent brick than %2 in. This was a tight specification, and one that would require slow and careful work to follow-but one that would assure a beautiful showplace floor. 

Some examples of such problems a major manufacturer of spaghetti sauce installed a very large brick floor laid with furan resin mortar over an asphalt membrane during July. During installation, the weather was hot and the humidity was at 100%. The unit was completed on a Friday afternoon, the weather changed and the temperature dropped 15° to 20°F. The plant was closed for a week with only a watchman on duty, and all doors and windows were shut. By the time the plant reopened, the temperature was back in the 90s. Two weeks later, inspection of the floor showed that the mortar was somewhat rubbery on the surface, but had hardened at the bottom of the joint-a sure indication of surface water. A check with the watchman disclosed that during the cold snap, enough water had condensed on the walls to run down over the floor and puddle all over it. By the time the plant reopened, it was all dried up and so had not been noticed. The floor had to be taken out and relaid. 

Resin Mortars This group includes the furans, phenolics, polyesters and the epoxies. Some of these mortars are used as thin membrane beds in lieu of asphaltic. Except for the epoxies and polyesters, most of these are acid catalyzed materials. The alkalinity of the concrete will retard the catalyzing reaction. Therefore, the concrete substrate must be neutralized before such a mortar is installed in direct contact with concrete. 

The selection of the resin is made in the same manner as the selection of the brick mortar, covered elsewhere in this volume, with the exception that the binder of the membrane must be a resin-not a silicate or a sulfur-and the order of choice is, first, the lowest possible shrinkage furan, then a phenolic and, finally, only if one of these two is unable to handle the chemical exposure, a vinyl ester or a polyester. 

A red shale brick or quarry tile floor is usually installed over a hot or cold applied mastic membrane. The mastic is applied to the concrete floor then the brick or tile are set with a resin cement. The resin cement can be a furan, a polyester or an epoxy depending on the anticipated exposure conditions. If high temperatures and constant exposure to aggressive chemicals are anticipated, the brick or tile will be bedded in the mortar as well as having mortar joints. 

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