Strap clamps are predominantly used with glue together floating floor installations that don't fit snug before the glue has a chance to set. They have also become an invaluable tool with the growing number of lower quality products being sold today. Shown to the right is an illustration of a coiled strap clamp manufactured by Crain Tools. Areas as large as 18 feet across can be brought together for a tight fit with this ratcheting mechanism.
Strap clamps were initially used in the flooring industry when glued laminate floors became popular. In the hardwood installation end of the business, these tools were never seen or used until a large number of manufacturers began to market a larger number of their products for the floating method. Prior to that period, most systems were milled with such precision there was no need for clamping. It was as basic as applying the glue into the grooves and tapping the boards tightly into place.
Nowadays these tools have been recognized by many professionals and are being used with other forms of installation, particularly direct glue downs.
How Are Strap Clamps Used?
Realistically when installing floating floors the first few rows can be glued, tapped together, then taped using blue painters tape. When the installation proceeds further into the room, place one side of the clamp (flat piece with curled edge attached with strap in photo above) on the edge of the starting area. It will overlap the edge. On the other end we want to engage the other part of the strap clamp near the end joints. Considering these strap clamps can be expensive here's a tip in case you have a product with many shorter pieces.
When extending the strap across the installed area grab a few longer scrap pieces (arrow), engaging them by tongue and groove on the last row without glue. By covering a few end joint areas with one longer board you've cut down on the clamps needed. The ratcheting mechanism and pressure should pull all the side joints tight, without the need for extra clamps.
How Long Until The Glue Dries?
This will depend on the product quality. If you have many bowed or twisted boards the clamps may have to be left overnight. Better quality products on the other hand, may just need additional taping once the floor is pulled tight. Be careful with the ratcheting system. Too much pressure can heave the boards near the last completed area. If additional pressured is needed, weights (extra boxes of flooring) can be applied across the last few rows that were laid.
How Many Strap Clamps Are Needed?
If you're dealing with shorter random length hardwoods, or hardwoods that are not milled very straight it may be necessary for one every two feet. However, finding how the material is milled or fits is not as easy as laying a half a dozen boards on the floor for a dry fit. Often you really do not know the quality until you've gone through a few boxes or cartons of material.
Some Job Examples
Engineered Glue Down