Ju wood why empty drum phenomenon？

The floor after laid, when you knock, can appear sometimes the phenomenon of empty drum, ju wood is not exceptional also, so what causes this phenomenon?

1, when laying mortar is not full or not will tap the extrusion dense ceramic tile, can lead to this situation, this is also one of the most main status.

2, grassroots gravel didn't clean up, also can appear gap leads to an empty drum.

3, fixed false, mainly wool board and keel, wool board and floor nails fewer or not firmly.

4, plank moisture content changes caused by unqualified cause shrinkage or adhesive solution.So be strict inspection plank moisture content and adhesive quality process is particularly important.In ju board when installation, the above several if not handled properly, it will cause empty drum phenomenon after laid, so be sure to specification.