Acclimatization of Hardwood Flooring I
Acclimatization of hardwood flooring is the process of letting
your wood flooring come to equilibrium with the moisture content
in the environment where it is being laid. One might ask first..
Well wood is like a sponge. It absorbs and give off moisture
constantly in response to the environment it lives in. Like the
sponge it expands and contracts in size to reflect gained or lost
moisture. But with a sponge we don't care what size it is as long
as it does the job. With flooring we do care.
Hardwood floors that absorb too much moisture buckle and look
unsightly. Floors that give off too much moisture shrink, creating
gaps between the individual boards and encourage moisture penetration
and the associated damage, below the finish. So this is not a
trivial conversation, but rather a key ingredient in a successful
hardwood floor installation.
So there are 3 key questions:
- Do you need to acclimatize your hardwood flooring?
- If you do need to acclimatize the flooring, to what relative
- How do I acclimatize my hardwood floor if I need to?
Do you need to acclimatize your hardwood flooring
prior to installation?
humidity varies with geographical location of the manufacturer
and customer, so change the numbers in the conversation below
to reflect your local relative humidity conditions.
So do you need to acclimatize your hardwood,
well that depends! Most of the
better hardwood flooring manufacturers dry their flooring to 45%
moisture content (the average relative humidity for Central Ontario).
They know that spring-winter variations can go from 35-55%, thus
they aim for the mid point.
Equally important fussy manufactures encourage
their retailers to store the material in humidity controlled warehouses
to maintain this moisture level. This is why much of the offshore
made product has problems. It spends 4 months in the hull of a
ship, picking up moisture before it gets to you.
Thus if your geography dictates a relative humidity
in this range of 35-55% AND your floor manufacturer equalizes
their flooring to this mid point, then the discussion need not
go any further.. you are ready to install your hardwood flooring.
For the rest of us, life is not perfect and your
flooring is not at the right "midpoint." so you must
address the humidity issue more seriously. Here's some examples:
1. Your local environment is different from the norm
i.e.. excessively dry or humid...like lakeside property, or dry
prairie weather etc. but remember we are talking about the yearly
2. Less expensive offshore flooring that you are suspicious
has not been dried adequately .
. . but then I don't really feel this is a good buy to start
off with... as it is very hard to get a floor consistently dried
across all boards, using your home environment as a dry kiln.
That's why I say no to acclimatization and everyone else says
yes. I agree with the principle and the NEED but not with the
feasibility of execution!
Now this is where it gets tricky. Our third key question was
how does one acclimatize a hardwood flooring? My first answer
is that it is not possible and you are best to discuss this matter
with your local flooring store and see if they either have a "brand"
or "style" of hardwood flooring that is fabricated under
conditions more suitable to your location.
As an example you might use an plywood based engineered floor
with its greater stability for more nasty environments, or a glue
down installation that with a good glue can control moisture absorption
If you still come back and want or need to
acclimatize a hardwood floor, use the link above for a
further information. I've also added a more complete discussion
for question number two on why you want to
acclimatize your hardwood floor to the midpoint
of your home's relative humidity range.
My own opinion is that for the best hardwood flooring installation,
flooring must be made to the correct moisture content-- at the
time of manufacturing -- to lay a consistent, uniformly moving
Hardwood Flooring Installation Techniques