Why Is My Window Sill Leaking?
Why Is My Window Sill Leaking?
Leaking windows at the bottom corner of the frame or where the glass meets the sill usually indicate cracked caulking or glazing. When caught early, this problem is usually repairable by removing the old sealant and replacing it. If the crack and leak cannot be repaired, a new sill or window may be required.
Any windows that do not come in contact with the interior finish should not leak. These include windows in bathrooms, bedrooms, laundry rooms, and other areas where an interior finish does not exist. If a window is leaking in an area where there is no interior finish to contact, the structural integrity of the window frame may be compromised.
Water leaks at joints where two dissimilar materials meet usually indicate water leakage from either a poor seal or from damage to the wood sill or header, masonry blocks, and/or flashing above the joints. The sill or header should be reinforced and any joint or flashing material should be replaced.
Nail holes in the sill face due to repetitive exposure to water can also be repairable by using a wood filler. However, this treatment may not always be satisfactory, as filler and nail holes may be visible. An alternative is to use additional flashing around the window for increased protection against water intrusion beneath the sill.
Water that penetrates a window sill can cause staining of the interior finish, which will usually discolor from moderate to severe depending on how much moisture is present in the interior environment and whether any external surfaces are painted.
How Do You Fix A Basement Window Sill?
- Dust can be removed with a vacuum.
- If the sill is stained, this may be due to either water damage or mold. In either case, you will need to remove the stain using an enzyme cleaner such as Nature Clean.
- Professional house cleaners can treat the sill with a dust-free spray made of hydrogen peroxide, water, and mild soap. It is better to use this type of solution rather than a dust mask because it leaves no residue inside the frame (which can cause discoloration or mold).
- Most window sills are made of wood, which can be damaged by water. You may need to replace the sill completely if it is moldy or stained.
- If the sill is plaster, you can remove the stain with a solution of hydrogen peroxide and muriatic acid (which is a mild form of hydrochloric acid), but this should only be done by an expert.
- If the sill is made of metal or plastic, you can scrape it off or sand it down.
- Dirt may be removed by dusting with a vacuum cleaner, using a brush made from your vacuum hose, or scraping it away using a sharp knife or a utility knife (which has a blade on one side).
