Sill Plate Repair & Replacement
A sill plate or mudsill is the bottom horizontal member of a floor system to which vertical members (floor joists) are attached. Sill plates are usually composed of lumber in sizes of 2″×4″, 2″×6″, 2″×8″, and 2″×10″. In modern construction, the sill plate is made of treated lumber and is anchored to the foundation wall. The bottom of the sill plate should be at least 6 inches above the finished grade to hinder termites and prevent the sill plate from rotting.
Sill plates installed prior to the 1990’s may be made of non-treated lumber, thus inviting termite infestation and dry rot. Sill plates are the first point of contact with moisture from the foundation and are the first floor component to deteriorate. In a wet or damp crawlspace, the foundation wall will “wick” moisture up the wall and into the sill plate via capillary action. Wet sill plates also transfer moisture to the floor joists and are “magnets” for termites seeking both food and moisture.
The Crawlspace Company has the edge over others involved in sill plate repair. After decades of experience, we have developed techniques whereby we gently lift the floor structure off of the foundation to install the plate. We lift the floor with hydraulics only the amount necessary to replace the sill plate. Many other contractors or handymen install the new sill plate improperly and cause more damage to be repaired later. We only apply the upward pressure necessary to complete the process.
Improper Repairs to watch out for:
- Notching the Floor Joist to install the sill plate
- 4×4 post beam technique from footing to joist
- Installing a 16″ piece of plate at a time by beating it in.
- Installing a smaller plate than the original
- Shimming each joist rather than installing new plate
- Installing a non-treated plate (we’ve seen it done)
Look out for bad repairs, Give The Crawlspace Company a call Today for a FREE ESTIMATE!