You Don't Have to Be Stuck in a Box: Sustainable Alternatives to Wood Framing

When you think of building a home, probably some of the first steps you think of are building the foundation and walls. Convention probably even has you thinking of some form of concrete block foundation with a wood frame wall. While these are the most common forms of construction for these components of the home, they are not the only way to build.


There are several nonconventional methods to build a home, and some of the methods can even provide benefits that the standard wood frame home cannot provide. If you have been interested in the sustainable movement for a period of time, I'm sure you've heard of the construction practices that stray far from conventional, such as Strawbale, Cob, Rammed Earth, and EarthShip. However, you may not have heard of some of the other techniques that are closer to conventional methods.

The following three methods can either be used in conjunction with or as standalone methods, but they all turn out a product that looks similar to a conventionally built home. Each has their pros and cons, but ultimately they are solid building practices for sustainable homes.

Structurally Insulated Panels (SIPS):

These are panels made of foam insulation sandwiched between two panels of oriented strand board, plywood or other panel siding. They are used to construct all faces of the building; floors, walls, and roofs. One of the main advantages of SIPS is because of the rapid construction that is possible with them. SIPS are engineered and cut to size off-site, limiting the amount of time on-site prepping the material. SIPS also speeds up the process because the insulation is included, so once the framing is up, several steps are already completed. Finally, the properties of the panels help seal the home better and reduce noise from the outside.

There are a few downsides to the panels. First, there is a large learning curve for everyone on the job and they must be kept dry - so flashing is critical. Also, they may require a crane to install. Planning for electricity in the home is also critical. The panels are predrilled for wiring based on wiring plans that are submitted. Many people may also point out that petroleum is used to make the rigid foam board that is vital to the component. However, this shows a common issue in all green products; if you look at them hard enough, you can bring into question their sustainability. One must look at the overall product in some cases, and the life cycle impact it may have.

Autoclaved Aerated Concrete (AAC):

AAC looks very much like a standard concrete block until you pick it up. AAC is made with a variation of concrete made with aluminum powder to create an increase in volume while trapping air. This trapping of air insulates the blocks and makes them surprisingly light. The blocks will even float! They're produced in 8” and 12” thicknesses, 8” high and 24” long. One of the advantages to AAC is that it can be easily cut on site with specialized handsaws, bandsaws, or just ordinary tools that are no longer sharp enough to cut wood.

One of the advantages of AAC, like SIPS, is that once the walls are constructed, the framing and insulation is finished. Some sources say that the 8-in block can have an insulating value as high as R-21! AAC is also fire-poof, mold-proof, insect resistant, and sound absorptive. The blocks are laid very similar to standard concrete blocks using a type of mortar. It has been found by some installers, though, that individuals that are trained in laying standard blocks have a harder time learning to install AAC than someone who has little construction training.

AAC is not all pros; there are some cons to this material. It has a large learning curve for electrical and plumbing trades. While AAC can float, it does absorb water over time. Once the water is absorbed, the blocks no longer have the insulating properties that it has when dry. For this reason, the blocks are not a good fit for below-grade construction. The blocks can be cut to run chases, but for someone who's used to working with wood and the cavities that comes along with that style of construction, the idea of having to cut through solid block may be a little daunting. Homeowners may also find it a little unusual hanging a picture or other items on a wall made out of concrete.

Insulated Concrete Form (ICF):

ICF is made of polystyrene forms that interlock like Legos. The forms are then filled with concrete to form the structure. They're typically not stacked more than four high at a time to keep a blow out from occurring. After the concrete cures, the forms are left in place to allow for insulation, space to run electrical and plumbing, and to act as a backing for drywall or stucco.

As with all these products, ICF creates a tight envelope, and it includes its own insulation. The construction techniques used to build with ICF are easy to learn, and it is much stronger than wood frame construction.

A few of the downsides to ICF construction:

• Retrofits are typically costly, as concrete saws must be used to make openings or move walls
• Curing the concrete can also cause humidity issues inside the home for a period of time during construction
• Pricing is also typically more than traditional construction.

As mentioned before, each one of these can be used independently of each other or together. I've had the privilege to visit homes that used ICF for the foundation, AAC for the walls, and SIPS for the roof. These homes took advantage of all the alternative construction forms to construct a very sustainable home! Each one of these construction methods has its own pros and cons, and you may find one may fit your style better than the other. Talk to individuals who have worked with and lived in homes incorporated with these technologies to see which one best fits you.

Sustainable Floor Options: There Are More Than You Think!

You've probably heard about bamboo flooring and its sustainable traits. While how sustainable bamboo truly is may be debatable, you cannot deny it has become very popular in the sustainable movement. Although bamboo may be the most popular, there are several other flooring products that you may want to consider. As with bamboo, each one of these products may have some debatable traits; however, they compare very well against traditional materials, and are worth consideration.

1. Cork Flooring
Cork is harvested from the bark of live cork oak trees, leaving the tree able to regenerate in 9 to 14 years. The flooring is not only made from a rapidly renewable source, but it is also made from recycled cork, from manufacturing waste of other cork products. Cork flooring comes in planks and tiles of varying sizes, and is a snap or glue down installation. Cork is soft and resilient, along with other properties, giving it very few non-sustainable traits. Pricing typically runs between $3.00 and $5.50/square foot for material.

2. Reclaimed Wood Flooring
This is nothing more than wood floors made from wood salvaged from other sites. The wood can come from usual and unusual sources, such as old barns, mills, bridges, and even storm-damaged trees. The wood can be found in varying species, including maple, oak, black walnut, and more. Depending on the source the wood may have an aged look that may appeal to some individuals. Installation is typical of standard wood floors. Pricing ranges from $4.50 to $18.00/square foot for material.

3. Linoleum Flooring
If you grew up in an older home or with parents used to older floors, you may have heard vinyl flooring referred to as linoleum, but this is not accurate. Linoleum flooring is made up of linseed oil, flax, jute, cork powder, wood flour, and natural pigments. Unlike vinyl, it is not made up of toxic chemicals! The material looks like today’s vinyl, but again it is much safer for the environment. It can come is sheets, like vinyl, or in snap tiles. Linoleum sheet goods cost about the same as high-quality vinyl, and the snap tiles are around $5.00/square foot.

4. Laminate Flooring
This is a product that has been on the market for several years; while it had some sustainable properties, it's being improved. Green laminate flooring is made up of a top wood veneer made from FSC-certified lumber, the middle section is made of fiberboard, and the bottom of a low- or no-VOC material. Other than that, the floor is same as the laminate floor we are all used to. Materials cost $5.00 to $7.00/square foot for the green versions.

5. Recycle-Content Tile
Tile is a common flooring material, but what is special about the recycled-content tile is that it is made from either recycled glass or nontoxic mine or factory waste. The tiles come in either ceramic, glass, or metal. Glass and metal tiles are typically used for accents or backsplashes rather than flooring. Cost vary greatly depending on the type of tile; ceramic can range greatly, from $10 to $33/square foot installed, recycled glass from $20 to $150/square foot material only, and metal between $35 and $75/square foot, material only.

6. Recycled-Content Carpet
While carpeting is a challenge to keep clean and wears out faster than most other flooring products, it makes up 70% of all floors in homes. There is a sustainable alternative with recycled-content carpets. These carpets are made from plastic soda bottles. The bottles are melted down and spun into fibers! The cost is around $53/yard installed.

7. All-Natural Wool Carpeting
An alternative to recycled-content carpeting is wool carpeting. The wool is softer than some synthetic fibers, and while it sounds bad, it captures and retains dust better than conventional carpet. This allows for the dirt to stay in the carpet until it is vacuumed instead of being released by everyday activity. The carpet can stain easily, though. Natural wool carpeting costs around $150/square yard installed.

These are just a few of flooring products available. There are several others that are coming to the market that will possibly be seen over the next year. Some of the new products may not be necessarily conventional, but they'll be bringing new looks and features to the home!

Sustainable Flooring? You Decide: Bamboo Vs. Hardwoods

There's been a lot of talk recently about bamboo flooring and its sustainability. This is primarily due to bamboo having a quick growth cycle. With bamboo touted as being a sustainable replacement for hardwoods in today’s remodels, one must step back and look at all the facts and make an educated decision as to whether bamboo really  meets their sustainable standards.

Bamboo comes in several different colors and styles. There are two basic varieties: engineered and solid. These styles will be very similar to their hardwood counterparts in installation. The solid planks can come in vertical or horizontal orientation, with the horizontal being harder.

Both types of flooring are very similar. They both come in similar styles, installation is almost exactly the same, and pricing is similar, with bamboo being slightly more expensive. Bamboo can also be refinished, and some individuals claim that they can even stain it, even though the generally available colors of bamboo come from either the natural color or a steaming process that darkens the color.

So, if both floors are similar in composition then their sustainable nature must be what differentiates them. This may be true; however, let’s look at some facts so that you can make an educated decision as to whether bamboo is truly more sustainable than hardwoods.

1. Hardness
Most bamboo dealers will state that bamboo is just as hard as oak, if not harder. The truth to this has come into question. It is understood that the darker bamboo flooring is less hard than the lighter colors because the steam process weakens the material; however, even with this, the manufacturers claim they're still as hard as oak. This may not be true. Also, on flooring products, the primary protector is the finish, and the hardness of the finish has been found to vary in bamboo. There are several testimonials that can be found stating how quickly the bamboo has worn out and dented.

2. Renewable resource
Both hardwoods and bamboo are renewable resources, even if one takes much longer than the other to regenerate - bamboo typically takes 5 to 7 years to mature, where hardwoods can be anywhere from 20 to 50 years. In this case bamboo is quicker to produce, but it also produces less material.

3. Cradle to Grave
This is where the majority of the argument comes into play regarding bamboo’s sustainability. The embodied energy in a product can cause items to become less desirable. Bamboo is primarily grown in Asia; therefore, it must be shipped around the world on container ships. Most hardwoods are harvested locally in the United States. Since bamboo is a quick harvest crop that produces less per plant, there are a large amount of harvesting resources that go into each ton of crop, which may end up being more than hardwoods. It can be even debated that hardwoods produce the same biomass per year as bamboo; they just hold on to it longer.

Also, as the crops become more desirable, forests are being cleared to make room for farms. Again, the impact of this may be debatable, but there is little quality control on the fertilizers and pesticides that are used in this hasty production.

Finally, if bamboo wears out faster, a homeowner may be more likely to replace it, leading to waste in the environment - unlike hardwoods, which have been kept in homes for hundreds of years.

4. Quality Control
There is little quality control with bamboo. As mentioned before, there are large variations in the hardness and durability of the products between manufacturers. This can lead to the above scenario of high turnover rates of the floors, and can also bring into question the sustainability of the product. The Forest Stewardship Council does monitor the production of hardwoods for several manufacturers, ensuring their sustainability; they only have one bamboo manufacturer on their list.

5. Indoor Air Quality
Since bamboo must be glued together, formaldehyde may be used in the manufacturing process. This can lead to off gassing in the home, adversely affecting the air quality. While hardwoods may contain more natural formaldehyde, this is typically offset by the glue in the bamboo.

There is still much debate about the sustainability of bamboo. As manufacturing changes, so will this debate; it is up to you, the consumer, to weigh the facts and research the manufacturers to determine if bamboo is the right product for your sustainable build!

What Goes Into Sealing a Crawlspace

Last week I discussed why to seal a crawlspace, so how about now looking at what goes into properly sealing the space? There are a large number of variations on how a sealed crawlspace is installed; while most just vary by quality, not all of them are proper. A sealed crawlspace is intended to provide 5 things:

1. Moisture management
2. Pest control
3. Combustion safety
4. Fire safety
5. Radon safety

There are a few items that are required to make sure your crawlspace is properly sealed and that you will get all the benefits that are intended:

1. Installation of a vapor barrier with sealed joints on the floor, piers, and foundation walls.
A minimum of a 6-mil vapor barrier should be installed, with all joints sealed via mastic or an approved tape. It is highly recommended that a higher mil plastic be used because the 6 mil will tend to tear and wear easier.

2. Seal all foundation vents.
No vents or openings to the outside should be present, other than an access door. Porch penetrations should also be sealed with an access panel or permanent material.

3. Provide a foundation drain.
A foundation drain is needed with a backflow preventer. It is a good idea to allow the drain to accept moisture from above and below the vapor barrier.

4. Insulate the floor or foundation wall.
Insulating the foundation wall is more efficient, but either the floor or wall is acceptable. Evaluate the situation and choose accordingly.

5. Air seal duct and floor penetrations.
Air sealing the ducts will help improve your home's efficiency, and sealing them and the floor penetrations help prevent air transfer between the home and crawlspace. This also helps with fire safety.

6. Vent appliances to the exterior.
Gas appliances should be direct vented or two-pipe vented in the crawlspace. Most vented spaces do not have enough makeup air for single vent appliances, and a sealed one definitely won’t. Direct venting is recommended.

7. Mechanical Moisture Control
There are several variations on this, including the use of HVAC ducts and dehumidifiers. If an HVAC supply duct is to be used, a backdraft damper is needed and no return ducts. This can affect the efficiency of the system, so check with an HVAC contractor prior to doing it. I tend to recommend a dehumidifier, as it is the least problematic.

Additional Item:
A relative humidity monitor is good addition to help you know that the system is operating properly!