If you're aiming for a "green" renovation, you need to ensure that the products you use give off low levels of volatile organic compounds (VOCs).
These are chemicals - such as formaldehyde - that are contained in many building and finishing materials and that evaporate quickly into the indoor air.
These gases can cause dizziness, headaches, eye irritation and asthmatic reactions, and at high concentrations, they can be toxic. Millions of people are sensitive to chemicals and even low emissions of VOCs can make them really sick.
VOCs are emitted from all kinds of products used in renovations - treated wood, insulation, adhesives - and from many finishing materials - carpeting, flooring, paint, cabinets and furniture. This is known as off-gassing.
New construction or renovated homes have higher levels of VOC emissions, but they do decrease over time as the gases evaporate and are dispersed.
Some products - such as spray-foam insulation - cure quickly and, within a few days, the VOCs are virtually gone, or are at non-detectable levels. Other products - such as pressed-wood cabinets - will off-gas for much longer. And, if the material is exposed to high temperatures or high moisture levels, the emission level will be higher.
MAKE BETTER CHOICES
Talk to your contractor and do your homework so you can make informed decisions about the materials you are going to use in your home. You need to find out what a product is made of and whether it off-gasses. Many building products - especially man-made ones - do. Glass, ceramic tile, metal, stone and other hard and inert materials don't release any VOCs.
Choosing solid wood over composite wood products that contain formaldehyde is a good idea.
Consider tile or hardwood instead of vinyl flooring, or natural carpet instead of a synthetic. If you can afford it, go for custom solid-wood cabinetry with a low- or zero-VOC finish.
Kitchen cabinets are usually made of medium-density fibreboard, plywood or particle board that contain glues with high levels of formaldehyde. And, they often have a sprayed-on finish that will emit gases for many months.
All engineered and manufactured wood products are made with adhesives and resins, and most of those will off-gas. That includes plywood, oriented-strand board, laminated beams, medium-density fibreboard and particleboard. If these materials are used in the framing and structure of the house, they'll be separated from the living space by drywall and plaster, which will help to some degree with off-gassing.
PAINTS AND ADHESIVES
Most paints contain VOCs - they are formulated with solvents to improve their application or durability. But now there are paints that emit low or no VOCs, and are almost odourless as they cure.
Be aware, however, that while base paint might have low emissions of VOC, the tints you have added might not.
Water-based products, such as latex paint and caulking, have lower levels of VOCs than solvent-based products. And cleaning the brushes and equipment you use with oil-based paints requires more solvents, so latex is the way to go.
How green is it?
Be careful when buying products that are labelled "low VOC."
The manufacturer might make that claim, but like calling a product "green" or "natural," it could mean anything. The "low VOC" designation on a product might just mean "lower than before," when in reality its emission level might be high when compared with similar products.
Buy products that have been tested and certified as emitting low levels of VOCs.
One standard to look for is the Green Seal, which indicates that a product has been rigorously tested and meets certain environmental standards.
Similarly, the Green Label certifies that such things as carpets and adhesives meet certain requirements on emissions of VOCs.
Mike Holmes is the host of Holmes on Homes on HGTV.
For more information, go to http://www.holmesonhomes.com