Read these 11 Controlling Moisture Damage Tips tips to make your life smarter, better, faster and wiser. Each tip is approved by our Editors and created by expert writers so great we call them Gurus. LifeTips is the place to go when you need to know about Waterproofing tips and hundreds of other topics.
The point of a waterproofing membrane is to protect a building's visual and structural integrity by keeping water where it belongs and out of where it doesn't. To do its job and achieve total "waterproofocity", a membrane has to be:
• Impermeable. The membrane must be impermeable to prevent the passage of water.
• Flexible - membranes need to withstand any normal movement that may occur in building structures.
• Durable. The membrane must be able to retain its integrity over a long period of time.
• Designable. The membrane must lend itself to design details in a building. It must be suitable for each specific application. If a membrane cannot be applied where needed because of structural details, it is useless.
• Breathable. The membrane must be able to breathe so that moisture vapors from building interior and substrates can escape freely.
• Bondable. The membrane must be able to bond easily and readily to tiles that are fixed directly to them.
• User-friendly. The membrane must be easy to apply, relatively lightweight, non-hazardous, and environmentally safe.
• Repairable and maintainable. In exposed areas such as rooftops, the membrane should require little maintenance, and in the event of damage must be easily repairable.
• Continuous. The membrane should provide a continuous film, without areas of weakness such as overlaps, which could prove to be a potential source of water entry.
• Resistant. The membrane must withstand environmental and climatic conditions.
You may be able to spot moisture in your basement just by taking a look, but it takes a pro to tell you how long before you will need a whole new basement floor. Great engineering minds have come up with bunch of tests that can tell them how much moisture content or vapor is coming through your concrete slab. These include:
• The Plastic Mat Test (ASTM D-4263)
• The Calcium Chloride Test (ASTM F-1869)
• Gravimetric testing
• Radio Frequency testing
• Nuclear Density testing
• Electrical Capacitance testing (moisture content meter).
As luck would have it, only two of these are actually worth a plugged nickel. Only the Plastic Mat Test and the Calcium Chloride test give an accurate reading of moisture vapor transmission over time, which is what ruins most floor finishes.
The other test methods are like those old Polaroid cameras that give you a snapshot of moisture contained in a concrete slab at a particular moment. For example, a slab may be damp from rain and test with a high moisture content, but several days, after the water evaporates, vapor transmission levels will quickly return to normal levels, if there is no other source of moisture. So, it's a wash.
No, you don't correct an improper grade by complaining to the teacher. We're not talking about that kind of grade. We're talking about the grade or pitch of the grass and shrub-covered dirt you call your lawn which needs to slope away from your home's foundation to prevent your basement from filling up with water.
You can correct the problem yourself, if it is not to extensive by following a few easy steps. Be advised, if correcting your grade involves a great deal of work and transplanting, consider having a professional excavator and landscaper handle it.
1. Scrape away loamy topsoil, then add soil or rearrange dirt as needed, using digging tools, an iron rake and a wheelbarrow. The grade should slope away from the foundation at least 1 inch per foot (2.5 cm per 30 cm) for a distance of about 3 feet (1 m) minimum but preferably 10 feet (3 m), and leave at least 8 inches (20 cm) of foundation exposed under the siding, more in snowy climates.
2. Plant grass next to the foundation and locate planting beds 5 to 6 feet (1.5 to 2 m) away from the building; or plant ground cover with a thick root system (which draws water out of the soil) rather than putting mulch (which holds water in) around the foundation.
There is a liquid membrane solution for virtually every waterproofing or vaperproofing situation. Here is a list of the most common. Consult a professional for advice on choosing the right product for your job.
• Mastic asphalt
• Two components polyurethane tar modified
• Two components tar epoxies modified
• Single pack moisture curing polyurethane
• Water based epoxy two part for hydrostatic pressure situations
• Polyester resin two parts reinforced wit fibreglass matt
• Flexible epoxy resin two parts • Bitumen latex modified single pack
• Acrylic co-polymer water based single part
• Acrylic co-polymer cement modified two components
When it comes to condensation in your basement, it's not the heat, it's the humidity. You can start controlling moisture damage by using a number of different methods:
• Insulate the water pipes.
• Heat the basement during the winter.
• During hot weather, use air conditioning to cool and dehumidify the air.
• Promote good ventilation—sunlight and free movement of air can quickly dry out a basement.
* Ventilation should be regulated according to the weather conditions.
During hot, humid weather or long rainy spells, windows should be closed because the outside air will probably contain more moisture than the basement air.
If you see seepage only after days of heavy rain, you may have a swelled aquifer on your hands. If leaks keep dripping for several days after the rain stops, you have a high water table (the top of an aquifer), an uphill spring or a perched water table (a small underground pond). A rising water table usually penetrates everywhere at once. Springs and perched water tables may enter along one wall. Whatever the source, you have to get rid of the water somehow. You can install a sump pump, or arrange to have your basement professionally waterproofed.
Sheeting membranes have been designed to cover completely any imperfections in the substrate or background. There are quite a few, but the most common include:
• Metal sheets in the form of lead, copper or stainless steel flashing or trays.
• Multilayer bituminous paper system with gravel topping for protection.
• Butyl rubber sheeting
• Semi-rigid asbestos asphalt sheeting
• Bitumen/polyethylene sheets
• E.P.D.M. Ethylene propylene Diene Monomer
• Chlorosulphanated rubber (Hypalon)
• PVC Polyvinylchloride
• Neoprene rubber
• Torch-on sheeting consist of layers of polypropylene bitumen modified.
It goes without saying that you should take care of water seeping into the basement before it damages stored items or fills the family room with mildew. Controlling the water's source is always preferable when attempting to block its entry. You can fix the vast majority of wet basements by controlling roof water and surface drainage. If you've been a day late and dollar short with your water control, you'll have to resort to controlling moisture damage through other means, which include a ton of products you can get at your local home center.
Chances are if the water you see in your basement is unrelated to either the weather or seasonal changes in the water table, your water service might be broken. The first step in controlling moisture damage is to find the problem. You can find out quickly enough by shutting off the house main and observing the meter at the street, or you can contact the local water utility for assistance.
Waterproofing membranes come in two flavors. You've got your sheet membranes, and you've got your liquid membranes. Naturally, which one you use depends on what you want to do.
Sheeting membranes will give you highly trafficable surfaces (you can walk on it) and provide some insulation. You can apply sheeting membranes to your basic substrate with an adhesive. You'll need to make sure your sheets overlap by about 4". You will also have to bond them to each other with an adhesive or heat welding. Be aware that the seams are the weakest point in the system.
In general, sheeting membranes don't resist exposure very well, offer little temperature stability, and don't recover well from deformation (like most of us.) What's more, if the substrate is water logged, you'll need to vent sheet membranes or you'll have a severe bubbling problems on your hands, which stresses out your adhesive, which could cause your adhesion to fracture.
As Aristotle said, nature abhors a vacuum. So do the holes in your foundation known as foundation or footing drains. Over time they can get clogged. You can remedy the situation yourself with your trusty garden hose if your system is equipped with clean-outs (access pipes that allow auguring, flushing and other cleaning tasks). If not, consult a drain-cleaning professional, and go back upstairs and watch the ball game.
|Jennifer Mathes, Ph.D.|