Weatherization/Water and Freeze Protection

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Water and Freeze Protection[edit | edit source]

Freeze protection[edit | edit source]

House features that are vulnerable to freezing:

  • Fuel line of external oil tank.
  • External hose bibbs, especially if they are dripping and the water supply was not turned off in autumn.
  • Pipes along outside walls.
  • Pipes traversing uninsulated spaces.

Ways to prevent fuel line and plumbing fixtures from freezing:

  • Drain outside hose bibbs and turn off water supply before cold weather comes.
  • In an emergency, provide temporary insulation - anything from leaves, to hay bales, to sheets of plywood, to a homemade shed.
  • Install electric heat wrap on the pipes.
  • Replace regular hose bibbs with “freeze-proof” hose bibbs.
  • Move the oil tank inside.

Make sure to protect water pipes in unconditioned areas from freezing during the winter! There should be no problems with pipes that are in the basement, and are nearby a basement furnace, and are away from any holes in the foundation that may allow outside air currents to blow direct on them.

Drainage (preventing soil saturation)[edit | edit source]

Reasons for water in the basement:

  • Saturated backfill (the most common reason). Soil saturation causes hydrostatic pressure. The pressure of the water forces the water through the foundation walls and slab floor (either through cracks, around the edges, or directly through the porous concrete). This shows up as persistent seepage.
  • Blocked footing drains.
  • High water table.
  • Condensation of interior humidity.

The key to a dry basement is to control surface water as well as ground water. The way to tell surface water and ground water apart is that surface water shows up in one area of the basement, whereas ground water (from a rising aquifer) usually comes up everywhere all at once, and leaves uniformly as well. Often, with groundwater problems, the water doesn't come up until after it has stopped raining.

Saturated backfill causes most of the water problems in houses. Effects of soil saturation around the perimeter of the foundation:

  • Saturated backfill can freeze, lifting the foundation wall and cracking the slab. This is called frost heaving.
  • Gutter downspouts that drain too close to the foundation can undermine footings. Parts of the house could shift out of place.
  • Moisture that enters the basement can cause all kinds of problems elsewhere in the house, even in the attic, such as warped wood, mold, rot, and peeling paint.

General drainage advice:

  • Don't use black flexible corrugated pipe for drainage. This clogs easily, doesn’t allow water to flow freely, and is weak and flimsy. Instead, use some type of PVC.
  • The best drainage material is crushed stone, especially if the pieces are relatively flat, such as with crushed shale. Pieces of crushed limestone are often irregular in shape, rather than flat. Do not use gravel, rounded river pebbles, item 4, or QP (quarry product) for drainage.

Ways to prevent soil saturation around your house:

  • Install swales (trenches) and French drains (trenches containing slotted PVC pipe and crushed stone, underneath a driveway, for example) to intercept surface water long before it comes close to the house.
  • Install footing drains using schedule 40 slotted PVC pipe, with the holes facing downward. Filter out silt by wrapping the footing drain with crushed stone, surrounded with filter fabric, surrounded with sand. Make sure the footing drains stay unclogged. Ideally, footing drains should have one or more cleanouts on the surface, and should open to daylight somewhere downhill from the foundation. Footing drains are much easier to install when a house is being built than after the house is built.
  • Make sure any pipes entering the house below grade are set in impermeable soil such as tightly-compacted, "hardpan" clay (not sand) where they meet the foundation.
  • The soil or material against the lower part of a foundation should have high percolability, and should have a way for water to flow away from the foundation, such as footing drains leading downhill. Ideally, you should have crushed stone against the lower part of the foundation with crushed stone and footing drains extending downhill from there. The worst type of soil to have against the lower part of a foundation is high-clay soil, because it holds water, stays saturated for long periods of time. When that soil is saturated, it tends to cause foundations to shift, crack, and buckle inward.
  • Correct settled backfill, which directs surface water towards the foundation. Instead, slope the soil away from the foundation. The soil that is on the surface around the foundation is called grading soil. The grading soil, unlike the soil against the lower part of a foundation, should be high in clay, tightly compacted, and at least 6 inches thick. Such soil is virtually impermeable to water, directs water away from the foundation, and allows air to easily pull moisture out of the soil during hot, dry weather. You can compact the soil yourself with a tamper. Make sure you compact the soil, or it will absorb and hold moisture, exactly what you don’t want.
  • Do not plant large, deep-rooted shrubs within 4 feet of the foundation. Do not plant trees anywhere near the foundation.
  • Water plants near the foundation early in the day, so that the soil has time to dry off before the water sinks too deep and lingers against the foundation.
  • Remove tree roots near the foundation, which provide channels for water.
  • Slope window wells away from the house, install bubbles over them to prevent water from collecting, or eliminate them.
  • If your house has no gutters and downspouts, install them, and keep them clean and free of clogs. Repair any holes, cracks, or other damage. If the downspouts detach from the gutters, reconnect them promptly, using sheet metal screws.
  • Don't use louvers to disperse water (so-called "clog-proof gutters"). They are the equivalent of having no gutters at all.
  • Do not allow gutters to drain against the foundation. Instead, install downspout extensions and connect them to 4-inch PVC that is buried underground, slopes downward, directs water at least 10 feet away from the foundation, and either opens to daylight or connects to a storm drain.
  • Do not tie gutters into footing drains! They will both clog.
  • You can tie gutters into French drains, but don't forget to install clean-outs in French drains. Check for clogs regularly.
  • Don’t install screens over the gutters or wire baskets in the downspouts. All they do is clog up the gutters.
  • Repair cracks or holes in the interior foundation wall with swimming pool caulk, hydraulic cement, or an expansive mortar. Do not use "waterproofing" paints, vapor barrier]] paints, or moisture sealants on the interior foundation wall. Hydrostatic pressure will build up and water will find its way through the weakest spots, causing the paint or sealant to flake and peel, and causing disintegration of the underlying concrete block.
  • If nothing else works, install an interior perimeter drain, also known as a "dewatering" or "pickup" system. This channels water, usually towards a sump pump, and is therefore usually dependent on electric power for continued proper functioning. Do not connect interior perimeter drains into the exterior footing drains – this could undermine the footings. You should never increase the amount of water next to your footings.

Sources and effects of water in a house[edit | edit source]

Water causes more damage to houses than anything else. The most important tasks in maintaining a house all involve protecting the house from the effects of water.

Paradoxically, water vapor from damp basements causes most attic problems.

Water vapor turns to liquid water when it reaches the dew point. Humid air reaches the dew point more easily than dry air.

Sources of moisture in homes:

  • Dirt floor basements and crawlspaces.
  • Saturated backfill, which causes seepage through foundation.
  • Wicking through concrete slabs in the basement or crawlspace.
  • Showers.
  • Clothes dryers.
  • Kitchen appliances.
  • Leaking or dripping pipes (supply pipes as well as drain pipes) and fixtures.
  • Leaks in roof, often near vents, pipes, or skylights, resulting from corroded, damaged, or missing flashing or shingles.
  • Leaks resulting from damaged siding.

Harmful effects of moisture in a house, especially if the ventilation is poor:

  • Warped wood. (Wood absorbs moisture and swells.)
  • Mold.
  • Rot. (Wood consistently kept at a high humidity will rot, as will wood touching the dirt for long periods of time. There are many different types of rot. Most are destructive. Even the presence of non-destructive types of rot can indicate conditions that are favorable to destructive forms of rot.)
  • So much water can condense in the attic that it starts leaking through to the ceiling below, as if the roof were leaking.
  • Ice dams and roof leaks.
  • Soaked, compacted, ineffective insulation (resulting from roof leaks, or from condensation within the walls). Moisture passing through insulation will often appear as condensation on the outer, cooler edges of the insulation. Eventually, if enough moisture condenses, the water will drip down and soak the rest of the insulation.
  • Moisture pushing through from the inside can cause blistered, chipped, cracked, peeling, and stained paint or siding, and popped nails, on the outside of the house. (External temperature and humidity conditions can also cause these symptoms, but excessive internal moisture drastically hastens their appearance.)
  • Termites and other insects.
  • Clammy feeling in the cooler months, muggy feeling in the warmer months.
  • When combined with excessive heat in the attic, excessive moisture can shorten the life of roofing shingles.