insulation

Drywall Is Boring by S. Joshua Brincko

One option that's not drywall...

One option that's not drywall...

Do you agree? Why is it boring? I think it's because you end up in a box with a flat ceiling, flat walls, and flat floors with no depth, texture, or unique shadow lines. It's ironic that there's plenty of depth and texture behind all that drywall, but we always cover it up. There's studs, plywood, columns, beams, etc, but we typically consider those items to be "rough framing" materials even though they can offer a lot of interest if not covered up by boring drywall. The problem is that normal studs and plywood for example ARE rough framing materials. In certain applications, these materials may be appropriate to celebrate instead of hide away. Fortunately, there are different options when it comes to rough framing materials. The studs come in different grades and appearances. If you are going to leave the studs exposed, you can spring for a nicer grade of wood that's straighter with nicer grain patterns and many different options of wood species. Instead of ordinary plywood, you could use a plywood with a nicer veneer of nearly any wood species you like. Alternatively, you could use tongue and groove boards (similar to flooring) instead of plywood. All of these items have so much more texture than drywall, but you may be wondering if it costs more. Well, it depends. Drywall is pretty cheap, but it does need cut, attached, taped, mudded, sanded, textured, and painted. The stud and plywood method needs none of that extra labor or material, so it can be cheaper. Studs and plywood are required regardless of your finish materials, but the difference is the quality of the studs and plywood if you choose to leave them exposed. You can spend a little more money on the grade of the studs and plywood to offset the money you're not spending on the boring drywall. 

Instead of drywall ... tongue and groove sheathing and exposed studs in an art studio.

Instead of drywall ... tongue and groove sheathing and exposed studs in an art studio.

Now you may be thinking about insulation. Where does it go if you're going for the honest look of leaving the framing exposed? Newer, more advanced construction methods, allow for insulation to be placed on the OUTSIDE. This is a great approach since the ordinary approach of putting insulation INSIDE the walls means your're leaving about 10% of your wall un-insulated. This is because you can only insulate the space between the studs, and the studs (which are about 10% of the wall) do not provide any substantial amount of insulation value. Additionally, typical insulation batts (the fluffy pink stuff we are used to seeing), will sag over time. This leaves the top part of the wall completely un-insulated, AND this is where most of the heat escapes your house in the winter since we all know from 4th grade science class that warm air rises. The thermal image below indicates hot and cool spots. Notice how the studs are visible as cold, and you can see the slumping of the insulation at the top of the wall. 

Thermal image of a stud wall.

Thermal image of a stud wall.

So how does insulating on the OUTSIDE help us? It's because we can use foam insulation boards that are continuous. This means there are no interfering studs which leave un-insulated strips every 16". The foam board also has a much higher insulation value than regular batt insulation, so it does not need to be as thick as usual. Polyisocyanurate foam boards (ok, say it out loud: Poly - Iso - Cyan - Urate) offer about double the insulation value, AND they are also impermeable to air and water infiltration when installed properly. This gives your house an air-tight seal, so you can really retain more of the heat indoors with less insulation since there's virtually no gaps left for heat to leak out. These foam boards also have a reflective coating to initially reflect the heat back indoors. Over top of the foam board, the next step is to add a strip called a nailer. This helps to hold the foam board against the wall while also providing a surface to nail the exterior siding. When nailing the exterior siding against the nailer, this leaves an air gap between the siding and insulation. I call this air gap a drain plane. Typical siding is nailed flat against a wall, and any leaks or condensation (like on the outside of a Corona bottle) gets trapped inside your wall. Since this moisture cannot escape easily, it starts to rot away the building and cause mold or mildew to occur. The drain plane prevents this. Water intrusion is inevitable, so we have learned over time to plan for it instead of ignoring it. Knowing the water will occur due to condensation since your house is warm inside and cool outside, we need to provide a way to evaporate the unwanted moisture. The drain plane allows for the airflow necessary to keep your wall dry, as well as to prevent a solid from touching a solid. In other words, siding is a solid material, and so is plywood sheathing. We also learned in 4th grade science class that heat is retained and travels more easily through solids than liquids or gases. By putting an air space between the siding and plywood sheathing, the heat cannot magically jump across from the solid plywood to the solid siding. There's a lot of dynamics at play here. This approach can work with any type of siding - inside or out.

Nailer strips attached over foam board insulation on the exterior of the building.

Nailer strips attached over foam board insulation on the exterior of the building.

So maybe you're not into the honest look of leaving your studs and plywood exposed. It's not appropriate for every situation. This means you're back to studs covered with drywall. Rather than finishing the drywall, it can be used as the underlayment for almost any building material. The cost of finishing/painting drywall is relatively inexpensive, so there's typically not a savings to cover the drywall (or backer board) with marble, tile, wood panels, metal panels, stone, translucent glass, etc. The added cost will result in a better result that gives you a durable material that functions well in your space, and that added cost can be strategically allocated to specific areas that require that added functionality. My approach to architecture involves finding those special spaces with special requirements, grouping them, and specifying the appropriate material to enable that special space to function as best as possible. (Form follows function).

Drywall is a conservative solution. Live a little.

If you’d like to learn more about our design process, visit www.josharch.com/process, and if you’d like to get us started on your project with a feasibility report, please visit www.josharch.com/help