Expert: Stephen Major - 9/8/2007

Question
QUESTION: Would you please explain how to acheive smooth walls using using gypsum drywall? My new walls were very smooth, until they applied the primer- now there is a medium texture. The contractor is telling me that spraying the primer caused texture, yet painting & drywall companies I have consulted independantly tell me that the paint sprayer should produce no texture. The rep for the paint brand that we used said they recommend spraying the primer on, but that it should then be "back-rolled" with a 3/8" roller. This, she said, will result in an almost smooth texture, which is the smoothest possible with these materials. I was told the paint should be applied the same way. Also- is there a reason we would need both a pva primer and another primer to go with the paint? the primer we thought would work on its own, and is recommended by the manufacturer for new drywall, is Benjamin Moore's Regal N216 acrylic. One final request: is there a recognized authority to resolve such issues? I have heard many refrences to "industry standards", which amazingly seem to support whatever point is being made by the person refrencing said standards....

ANSWER: Brandis,

It is common to have a conflict between the expectations of a customer and the results of a contractor's work.  Painted drywall nearly always has some level of texture from the painting process.  Spraying with backrolling is pretty much an industry standard, with the nap of the roller and the thickness of the paint film being the prime determinants of the final texture.  A longer nap will give more texture, but a thicker coat will generally run together better for a smoother texture.  

One primer coat is usually all that is needed in new work.  I prefer the slightly more expensive USG "First Coat" primer, which reportedly contains some drywall joint compound.  It equalizes the porosity of the drywall (between the raw paper surface and the finished joints).  

For the very best results, have the contractor sand the dry paint film between each coat, starting with the primer, then the first finish coat.  The second finish coat is left unsanded.  I don't recommend skipping the second finish coat, although your contract may stipulate just one coat over primer, in which case you would pay a upcharge or change order for additional coats beyond the contract.

Best of luck and let me know if you have additional questions.

--Steve Major

---------- FOLLOW-UP ----------

QUESTION: Thanks-

The problem I am trying to resolve is how to convince the contractor that a mistake was made. On the label for the roller, the 3/8" one indicates it is for SMOOTH walls, and the 3/4" indicates it is for light to med textured walls. Can we look at the texture that was created, and determine that the roller used was too thick a nap dimension? Is there a written specification that can be referred to that explains how much texture is acceptable on a wall that can still be considered "smooth"?

Does spraying itself result in texture? It was my understanding that spraying with the correct air nozzle will result in no texture, and yet the contractor insists that spraying actually causes texture.

Lastly, what can be done at this point to get the walls back into a smooth condition?

Answer
Brandis,

I am not aware of any readily available standards that describe what you are looking for.  The CSI (Construction Specifications Institute) does publish a lot of standards.  They are available for purchase on their website, as well as at some larger public and university libraries.  

Spraying too lightly can cause a bit of texture.  The paint dries too quickly, and is too thin, to flow together well.  One 3/8 nap is not necessarily like another, so resulting textures will vary.  Also, the texture described on the roller cover is typically describing the PRE-PAINTED condition of the wall.  Smooth drywall can be painted with a 3/8 nap roller, but a 3/8 nap will not reach down into the nooks/crannies of a textured wall.

A light texture is typical with latex paint on drywall.  It can be minimized (but not easily eliminated) by sanding between coats, using a low-nap roller loaded with adequate paint, and using enough paint overall so the coat flows together.

Spraying can result in a smoother coat, but it may be uneven or prone to running, on a large surface such as a wall.  This is why a back-rolling step is used.  Spraying enamel on trim is a different process, as the much smaller area is easier to manage and thus a smoother coat is possible.  

--Steve Major