Wednesday, October 5, 2016

Wood and Not Wood

I am a residential architect, so my projects are built mostly out of wood. For example, we don't tend to frame houses with metal studs or build house walls out of masonry (brick or stone) -at least in my area. Some parts of a house that have traditionally been made from wood are now being built from non-wood materials (that look like -or try to look like- wood). Sometimes the material swap is for reasons of durability or sustainability. Sometimes it's to make construction easier or to reduce future maintenance. Sometimes using non-wood is a necessity, as in when wood is not strong enough for supporting open spaces and long spans or a village or city has a fire code.

Here are some photos from various projects illustrating this point.

Decks are a common place that, in today's home construction, wood has been replaced with various composite materials with success. This Trex composite material has integral color, concealed fasteners, recycled content, and is virtually maintenance free and easy to install. Being on the southern side of the house, it will have to deal with a lot of UV, so using non- wood makes sense. It makes sense on the shady side too, since nobody likes mildew on their deck. And it makes sense in a home that folks want to grow old in and hope to reduce the work they need to do to keep things in good shape.

Clapboards and other siding materials that were traditionally made from wood boards are often now made of cement on many, but not all, of my projects. Cementitious siding, such as those made by James Hardi, is durable, fire-resistant, rot/mold resistant, and installs similarly to wood siding. In addition it can be ordered with a factory-applied baked-on finish in your color of choice. That finish should last for many, many years longer than paint lasts on wood. Like the Trex decking material, it can still look traditional and carpenters can use the same tools and some of the same installation methods they are familiar with for installing Hardi siding.

High-Tech Material that can look quite traditional
Installing Hardi Siding is just like installing wood siding

Wood is still the primary material I specify for framing. (unless the loads are too large, and steel must be used for its superior strength) In addition to various grades and species of 2x material at the lumberyards, we also have choices like engineered lumber, which is super strong compared to simple sawn lumber. It's made in a factory from pieces of wood and glue and also comes in many grades and looks, like beams and I joists.

Most of the House Framing is 2x sawn lumber

At the NHND to the Mountains, I had to use a steel beams to hold up both the second floor over an open kitchen/dining space and the roof over an open wide dormer. The steel I beam is nothing nice to look at, and super heavy to install. Holes come in it so wood can be bolted to it so that we can attach finish wood trim or sheet rock to box it in and cover it up. (it becomes invisible!)

Hidden Steel Beam holds up roof (top left corner of pic)

At the NHND to the Pond, we have some "ugly" and some "pretty" wood beams carrying loads that regular sawn lumber couldn't handle. Wood beams can be covered up with other finish materials (like the wall studs and roof rafters are covered with sheet-rock inside or trim boards outside) If they will be covered, I use LVLs - which are strong and readily available, but not so pretty; they look like a stack of plywood. I can also use ugly metal fasteners, if I know they will be concealed from view.

Hidden LVL beam supported w/ metal joist hangers
 is above ceiling line and will be covered by ceiling

But sometimes, we want wood beams to be exposed and become an architectural feature in the space, not just a hidden item holding things up. That is the case in the open Living Room and Kitchen area. Like many houses being built today, the floor plan is open front to back, and a long beam was needed to hold up the floor above. Rather than use an LVL and cover it, I specified an "architectural grade" or "appearance grade" glulam beam. It is beautiful and strong, and we can sand it, leave it exposed, and wipe a varnish finish on it for protection. It, along with the wood staircase and wood windows in the corner of the Living Room, will contribute to the homey feel of the space.

Exposed Glulam wood beam supports floor above and creates
a distinction between LR & Kitchen in open plan
Exposed Glulam wood beam supports roof-
(R&L This is NOT your house :)
Wood Beam above Metal Frames for Double Pocket Doors
Another place that we find metal instead of wood in my projects is pocket door frames. I like using pocket doors, and this house has 5 or so. They don't use up space the way a swing door does, so, like built-ins, they are worth having when you are designing small. And in the case of a wide pair like we have between Kitchen and Office, they can enable the floor plan to have flexibility so that rooms feel wide open to each other if you want or they can be private when you need. They are also great in toilet compartments or for openings that may rarely get closed, like the mud room/hallway connections.

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