Use a notched trowel to spread the adhesive.
Too much glue hardwood to concretr.
Glued down floors are also not a good fit for below grade concrete or high moisture subfloors which are often found in basements.
This is a common mistake with newcomers to the do it yourself hardwood flooring field.
The adhesive manufacturer should have instructions regarding specific trowel requirements.
Glue forms the initial bond but without screws and nails the natural expansion and contraction of the wood can break or weaken the glue.
They use too much adhesive thinking that more is better and the panels will be more secure this way.
The weight of the glue and planks can become too overwhelming for the lightweight concrete or gypsum and ultimately lead to disastrous results.
If there are voids the boards can flex into them and make creaking sounds as they rub together.
A vapor retarder is required for installation over concrete with a calcium chloride reading greater than 3 pounds a relative humidity reading of greater than 75 or a calcium carbide cm reading of greater than 2 5.
Floated subfloor system 1.
When you glue a hardwood floor to concrete the subfloor must be completely level.
Installing engineered hardwood flooring over concrete too tight against a stationary object will not allow room for normal expansion and may cause a failure.