over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This

The condition of the paint or stain on your buildings can be your ambassador of curb appeal. Its appearance can say a lot about your condominium community. And yet you could be spending a healthy portion of your maintenance budget on a much too short re-coating cycle. Every trustee and property manager will agree that keeping a paint or stain film on exterior wood is a never ending job. One of the truisms that go along with this effort, however, is the fact that each building can be different in how it holds paint or stain film. Identical building configurations oriented differently to sun, wind and rain will expose a coating differently.

And too, identical configurations with identical orientations but different interior moisture movements will shed their films differently. You can be using a high quality product applied by skilled craftsmen and still be fighting only half the battle. Water is the enemy, whether in the form of bulk water or migrating vapor whose strategy needs to be understood in order to defeat it. Let’s see if we can identify some things we know about building behavior that may help your situation. Water’s principle tactic is divide-and-conquer. It wants to get between the film and the wood the film is intended to protect. The water source can be either exterior bulk water or vapor migrating from the building’s interior through the exterior wall cavity to the siding. Easily the most common source of exterior water is roof run-off that runs down the exterior wall because there is limited or no roof overhang. Entry into the wall cavity can occur through gaps in the siding and around window and door casings.

The cut ends of clapboard siding, if left unprotected by corner boards, will wick up water. Those ends should be protected. Even if you have corner boards, caulking between siding ends and the boards is a wise precaution. Water coursing down clapboard siding can be drawn up by capillary action into the wall cavity, defying gravity. The extremely almost invisible gap of one siding course over the next forms that needed channel. The water is stored inside the wall against the vapor retarder and perhaps sheathing if there are breaks in the vapor barrier. When the sun heats the surface of the siding the water vapor is pulled out through the siding by vapor pressure, lifting the protective film and blistering or cracking it. Wind will aid and abet this process by holding the water against the building thus assisting the capillary action. Never paint the gap at where one course of siding overlaps another. That paint will crack eventually when the siding sees thermal expansion and now you’ve got a capillary pathway.

If those overlaps are currently painted you can insert small wedges, specifically made for this purpose, into the overlap to enlarge the opening thus defeating the capillary action. Wind can even drive run-off under wood shake siding. In a study we did for a new construction building on the Maine coast we found salt water driven up under the shake siding. The sea was 50 feet away. The solution, unfortunately, was to remove the siding, install a rain screen over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This

y. You can be using a high quality product applied by skilled craftsmen and still be fighting only half the battle. Water is the enemy, whether in the form of bulk water or migrating vapor whose strategy needs to be understood in order to defeat it. Let’s see if we can identify some things we know about building behavior that may help your situation. Water’s principle tactic is divide-and-conquer. It wants to get between the film and the wood the film is intended to protect. The water source can be either exterior bulk water or vapor migrating from the building’s interior through the exterior wall cavity to the siding. Easily the most common source of exterior water is roof run-off that runs down the exterior wall because there is limited or no roof overhang. Entry into the wall cavity can occur through gaps in the siding and around window and door casings.

The cut ends of clapboard siding, if left unprotected by corner boards, will wick up water. Those ends should be protected. Even if you have corner boards, caulking between siding ends and the boards is a wise precaution. Water coursing down clapboard siding can be drawn up by capillary action into the wall cavity, defying gravity. The extremely almost invisible gap of one siding course over the next forms that needed channel. The water is stored inside the wall against the vapor retarder and perhaps sheathing if there are breaks in the vapor barrier. When the sun heats the surface of the siding the water vapor is pulled out through the siding by vapor pressure, lifting the protective film and blistering or cracking it. Wind will aid and abet this process by holding the water against the building thus assisting the capillary action. Never paint the gap at where one course of siding overlaps another. That paint will crack eventually when the siding sees thermal expansion and now you’ve got a capillary pathway.

If those overlaps are currently painted you can insert small wedges, specifically made for this purpose, into the overlap to enlarge the opening thus defeating the capillary action. Wind can even drive run-off under wood shake siding. In a study we did for a new construction building on the Maine coast we found salt water driven up under the shake siding. The sea was 50 feet away. The solution, unfortunately, was to remove the siding, install a rain screen over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This

cavity can occur through gaps in the siding and around window and door casings.

The cut ends of clapboard siding, if left unprotected by corner boards, will wick up water. Those ends should be protected. Even if you have corner boards, caulking between siding ends and the boards is a wise precaution. Water coursing down clapboard siding can be drawn up by capillary action into the wall cavity, defying gravity. The extremely almost invisible gap of one siding course over the next forms that needed channel. The water is stored inside the wall against the vapor retarder and perhaps sheathing if there are breaks in the vapor barrier. When the sun heats the surface of the siding the water vapor is pulled out through the siding by vapor pressure, lifting the protective film and blistering or cracking it. Wind will aid and abet this process by holding the water against the building thus assisting the capillary action. Never paint the gap at where one course of siding overlaps another. That paint will crack eventually when the siding sees thermal expansion and now you’ve got a capillary pathway.

If those overlaps are currently painted you can insert small wedges, specifically made for this purpose, into the overlap to enlarge the opening thus defeating the capillary action. Wind can even drive run-off under wood shake siding. In a study we did for a new construction building on the Maine coast we found salt water driven up under the shake siding. The sea was 50 feet away. The solution, unfortunately, was to remove the siding, install a rain screen over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This

blistering or cracking it. Wind will aid and abet this process by holding the water against the building thus assisting the capillary action. Never paint the gap at where one course of siding overlaps another. That paint will crack eventually when the siding sees thermal expansion and now you’ve got a capillary pathway.

If those overlaps are currently painted you can insert small wedges, specifically made for this purpose, into the overlap to enlarge the opening thus defeating the capillary action. Wind can even drive run-off under wood shake siding. In a study we did for a new construction building on the Maine coast we found salt water driven up under the shake siding. The sea was 50 feet away. The solution, unfortunately, was to remove the siding, install a rain screen over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This

over the vapor barrier and then replace the shake siding. The point here, so transparent in hindsight, is if you’re building in an extreme site, take extreme precautions. This also reminds us that wind can drive water through any break in the exterior envelope. Closing off any break in that envelope such as around windows, doors, vents with caulk are important. Melt water backed up behind ice dams can find its way down into the exterior wall. The wet insulation in the wall cavity stays wet until the warmer weather when drying action draws its moisture out through the siding. Introduction of outdoor air to the roof underside through attic ventilation usually cures the problem.

Interior moisture in the form of migrating vapor needs to be encouraged to make a quick exit. This is best done by structural ventilation, the most common being the combination of soffit and full ridge vents. This construction augments the natural tendency for air to rise in a building by convection and pressure differential. Wind blowing across a ridge vent or perhaps through gable end vents creates a negative pressure there that pulls air (and water vapor) up from below and sends it out doors. If that mechanism is not in place or is compromised in some way water vapor sees the wall cavity as the path of least pressure. The vapor condenses out as water in the cooler wall and is stored for eventual passage out through the siding and lifting the protective film. It goes without saying of course that any moisture generators such as clothes dryers and bathroom fans should be vented directly to the outdoors.

By the way, never assume that a bathroom fan with a humming motor is actually pulling air. The humming may be a seized bearing or the fan may need cleaning. Check it out. Kitchen fans are, in my opinion, not given sufficient credit for their potential for moisture removal. Clearly cooking generates moisture. Ever open a dishwasher while it’s running and be greeted by a cloud of hot vapor just looking for a place to condense? Address your water and moisture problems first and you will enjoy the length of protection and appearance your buildings need to project the image of a well maintained community.