Concrete is a porous material that allows water to move through it and many foundations have cracks. You need to reduce the moisture from moving outside your foundation and into your basement. Proper waterproofing on the outside of your home will ensure that your basement will stay dry. Regularly check your down spouts to be sure that the water is moved away from your foundation. Check your foundation for cracks and whether or not those cracks show signs of leaking. Leaking cracks can be fixed from the inside and a good contractor will guarantee that it will never leak. If your basement has a sump pit and pump be sure that the pump is functioning properly. It's a good idea to set up a back up pump in case of a failure.
Check that your HVAC system is set up properly for your basement design. Most new home builders only install the minimum requirements for unfinished basements and do not consider future changes. Make sure each of your new rooms have a heat vent before its too late. While you consider changes and upgrades to the system also consider the design of the bulkheads to cover all the ducting.
When insulating your basement you must consider both water and temperature. Different insulation practices may be considered for your basement depending on your situation. Many consider urethane spray foam the best option for basements but it can be a higher up front cost; so do your research on what is best for you. If your home has been insulated with roll-on blanket style insulation; it must be removed prior to framing. Basements are required to have an insulating rating of R20 in Ontario as of January 2012.
Some people think it's a good idea to install moisture and mold resistant drywall in their basement. This would be a good idea except that if you are worried about mould on your drywall then it is already too late. Fix the moisture problems first. Mold and Moisture drywall is good for areas like bathrooms where you are adding moisture to the room. Unless you plan on adding moisture to your basement; save your money.
Your floor is another area of concern for your basement. Check it for cracks and signs of leaking. If you have moisture coming up through the cracks in the floor then you have a water table issue. Your sump pit is used to pump out the extra water from under the floor and around the foundation. If you have water coming out of the floor then this is not working properly and you need to fix this first. Sub floors can add R value and protection from leaks. There are many options now that will work best in different situations. Never install a floor directly on concrete unless it is approved by the manufacturer and you have any water issues fixed. If you want to install tile on the floor consider in-floor radiant heat.
By Brent Darlington