41. The use of expansion joints in sidewalks may not be necessary, as the concrete will shrink while setting. 42. If there were no gap ( it's called an expansion joint ), the boards would buckle when they expanded. 43. This is not to suggest that the expansion joint that crashed into the seats was anything but an accident. 44. The ECC patch was used as a replacement to the previously existent expansion joint that linked two deck slabs. 45. At the expansion joints , commercial-grade polyurethane sealants keep water out and adhere tenaciously, if the joint is thoroughly cleaned. 46. If there were no expansion joints , cracks would appear willy nilly, and you would have a mess on your hands. 47. Usually this expansion joint is covered by the baseboard or a shoe mold, a quarter-round molding nailed to the baseboard. 48. This expansion joint , about 1 / 2 inch wide, allows the tiles to move into this space when they expand. 49. This is an expansion joint , space for expanding boards ( they swell when they absorb moisture ) to expand into. 50. Hydrophilic strip applied waterstops should not be used in contraction or expansion joints per the instructions of most commercial manufacturers.
