Window sills take quite a beating. Constant exposure to the sun, rain and ice can take a toll, especially when water finds its way beneath the layer of paint and caulk. Ongoing exposure to moisture can cause the sill to rot, a process that only gets worse over time. If left unchecked, the rot will penetrate deeper into the sill, requiring more and more extensive repair, often spreading to adjacent jams and trim-work.
The good news is that repair isn’t too difficult, especially if performed early enough. If the rot is confined to just a small area, a simple patch and fill is all that is needed. For larger sections of damage, most or all the sill should be removed and replaced.
Check to see how extensive the rot has become. You’ll have to remove any rotted material, so if it extends to the window trim, cut out any rot you see there as well. It is best to make a clean cut at the edge of where the damage is, thus leaving an even surface of hard wood to work with. If the damage runs along the entire front of the sill, it may be necessary to cut the sill off, leaving it flush with the siding. A circular saw will work well for this.
To repair a small section, first scrape away any remaining paint and caulk from the affected area Dig way the rot and tighten up the remaining wood with a wood hardener. Once the surface is prepared with a hardener, use a two-part epoxy wood filler next, such as Minwax High Performance Wood Filler to either fill small areas completely or to build up the surface enough to attach a new sill or piece of trim. If you had to remove the sill flush to the siding, do the following:
As with any repair project, we’re here to help. Just stop in or give a call and we’ll be happy to answer any questions you have about window sill repair or any other project you’re working on.
