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 Hamilton Drywall
Products is proud to introduce Prep Coat Plus "Level 5" as our newest addition to
our paint line. Click here for more information! |
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| Delamination of
texture on drywall surfaces is an expensive and apparently increasing problem. Job site
investigation of this problem reveals not one cause, but
several. Read more >>> |
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| Spraying Acoustic Ceilings-Problems and Solutions |
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By Patrick D. Comer
The
author was formerly owner of the Hickenbottom and Comer Co. in San Diego (CA) County. Currently he
is in the remodeling business in San Antonio (TX).
Today is more the norm than the exception
in new home construction for the ceilings to be given that "modern" look of sprayed on
acoustic ceilings. And older homes that are without it are increasingly having acoustic blown on
their ceilings.
Even though sprayed on acoustic ceilings seem to have come of age there
are critics who say its advantages do not outweigh its disadvantages. Let's address ourselves
to this question and consider the advantages and the problems associated with blown acoustics.
One advantage, at least to most, is its aesthetic value. It looks nice and provides good contrast
to wall textures, paneling, or wall paper. It brightens rooms and gives the appearance of enlarging
them. Also, in the initial construction costs both time and money are saved. The blown acoustic
can hide a multitude of sins in the drywall taping and floating and generally requires less
ceiling preparation. Home builders have also found blown acoustic to be a good selling point
for their new homes.
In new home construction, practically all of the acoustic is
actually a simulated product rather than a functional acoustic. Normally, the advantages of a
functional acoustic over a simulated acoustic do not seem to warrant the difference in cost.
The finished appearance is about the same, with the main difference being in sound ratings and
flame spread ratings. But the problems associated with its application are about the same, so the
suggestions will, for the most part, apply to both.
On the average, blown acoustic ceilings
are either spray painted or reblown every 12-15 years. Of course, this average can vary greatly,
depending on the type of heating used, how clean the filters are kept, whether the homeowners
smoke or not, etc. The choice of whether to spray paint acoustic depends on the condition of
the ceiling. But when it does require a repair job or just a whitening up, it usually becomes
apparent to the average homeowner that a competent contractor is needed to do a professional
job.
For many contractors accustomed to new home construction, the prospect of reblowing
an existing ceiling, with the people living in the home, can be a veritable nightmare. And, to
the dismay of both the contractor and the homeowner, it sometimes becomes one when the contractor
fails in the most important aspect of reblowing acoustic ceilings - the masking!
Two thirds
of the time allotted for the job will usually be spent on masking. Often a combination of masking
paper, 1 mil plastic, and canvas drop cloth is used. Some contractors have substituted plastic
for the canvas drop cloths, thus eliminating the need to vacuum the dust that accumulated in the
canvas drops and then falls on the carpets.
Proper masking technique cannot be over
emphasized. If great care is not taken in the masking process, the end result may cause the
homeowner to lose sight of the fine job done on the ceiling due to the mess which has smeared
on the rest of the room and its contents. It is the prudent contractor who realized that herein
lies the success or failure of most jobs.
Another problem that plagues contractors spraying
acoustic is that of discoloration. This is a common complaint, but with an easy solution, compared
to having to go back and respray the ceilings.
There can be several causes for a discolored
ceiling but these can be identified easily. Circular rust-colored stains or rust-colored joints may
indicate leaky plumbing or a bad roof. Solution? Seal with a white pigmented shellac and respray.
This sealing process is recommended on old plaster ceilings even though no stains are visible. Even
very old water stains could leach through if the ceiling was painted with a water-based
paint.
But in speaking about ceiling discoloration, by far the most common problem is a
difference between the joints and the field of the board of drywall ceilings. This problem has been
referred to as "photographing", "burning through", "banding", or a
"bleedthrough". For a long time no one really knew why the problem occurred, though many
blamed it on faulty material. But that was like betting against the house, it seldom was
the reason.
To find the reason for the problem, Hamilton Materials of Orange, California,
commissioned National Standards Inc. Laboratories to do a series of tests. They filed the results
of these tests on August 28, 1979 with Hamilton Materials. Hamilton Ceiling Texture as well as USG
Ceiling Texture had been applied to the individual pieces of wallboard. Each of the sampled coatings
was discolored by the wallboard. The question was why. The report concluded, "The most probable
cause for the discoloration of the textured coating is the wallboard paper contains organic sulfates
such as lignin, tannins and gluosides which are water soluble and can be leached into the wet textured
coatings as the solvent system evaporates". The report also noted, "Any conditions which
would enhance slow drying would aggravate this situation; i.e., high humidity, poor ventilation,
etc.".
With this information at hand, how can the ceiling contractor correct the
problem - or better yet, prevent it? To answer the question, Hamilton Materials sent a letter to its
customers on the subject "Color Differential Between Joints and Field of Board on Textured
Drywall Ceilings". This letter reflects the thinking of most ceiling texture manufacturers
concerning the application recommendations. The letter stated that "the only real solution
to the problem is to seal the entire ceiling surface prior to the application of texture. This
has been a recommended procedure for several years but has not been followed in actual job practice.
With this new evidence and the magnitude of problems being encountered, it would seem almost mandatory
that the recommended sealing operation be made a standard procedure in the drywall finishing
process".
The type of sealer used may vary with the needs of each job, but usually a
pigmented shellac or an alkyd-based sealer is recommended. It would be well to check with the
manufacturer of the ceiling texture you use as most of them will not guarantee the product unless
the surface is sealed first.
As commented on previously, many contractors have failed to
follow manufacturers recommended procedures. Perhaps this is due to strong competition, or just
a gambling nature on the part of the contractor. But in light of information presented it would
seem that the competent contractor would follow these recommendations whenever possible.
So
whether the contractor is blowing acoustic in the initial construction of a home, or years later,
if these common sense suggestions and manufacturers' recommendations are followed the contractor
will be "cents" ahead. |
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