We recently had the privilege to work on an eco-roof, which is a type of living roof that combines a waterproof membrane roof with a lightweight soil mixture on top and that allows you to grow shallow rooted plants on the roof. It has many environmental benefits and is a great way to greenify your home.

In the Pacific Northwest waterproofing problems are probably the #1 source of construction defect lawsuits. These lawsuits are bad for contractors and we all pay the price in the form of increased insurance rates which translate into higher construction costs for consumers.
The secret of waterproofing exterior walls is not some newfangled technology, but rather an evolutionary thinking about how we incorporate technologies that we have been using for decades. Academic tests and studies on the science of waterproofing exterior wall systems are freely available, yet many contractors still don’t follow these proven techniques.
The basic lessons from these studies are that we need to design for failure. That’s because it doesn’t matter if you use the latest and greatest Hardiplank cement board siding or cheap vinyl and aluminum siding, at some point the combination of wind, water, and gravity will cause water to get behind your wall. The secret question is, did you plan and design for the water that you’ve now got behind your siding? If you did, your wall system will have incorporated the following four elements:

Drainage plane – heavy felt building paper or housewrap
Drainage space – furring strips, stuccowrap + felt, two layer felt, or air gaps
Flashings – metal flashings to kick water out
Weep holes – openings to allow water to escape

If your wall system includes these four elements and it is well constructed, then you shouldn’t have any waterproofing problems.

When contractors talk about Green Lumber, they are usually referring to lumber that hasn’t been kiln dried or seasoned. This means that the lumber is still wet inside and full of sap from the tree. It is an all too common practice in the Northwest to use green lumber for rough framing due to our proximity to the lumber mills and the fact that it is cheaper than kiln dried lumber. However, the problem with this practice is two-fold.
The first problem is that as wood dries, it changes shape and warps. Depending on the severity of this process, it can cause the entire structure of your home to warp over time, which is one of the common causes of cracking in the drywall or plaster on your walls.
The second problem is that in can take years for green lumber to dry, and over time wet wood is likely to grow mold! The combination of the heat from your house and the moisture trapped in the lumber in the walls creates a friendly environment for a not so friendly fungus.
Now it’s important to note that not all “green” lumber is bad. I say this because some people may refer to lumber that came from sustainable forests as “green” lumber. I will talk about sustainable lumber more in a future article, just make sure that any lumber you get is kiln dried or seasoned before you use it to build or remodel your home.