How to Replace a Window Sill

It is observed that wooden window sills are the fist to get spoiled or rotten in a house. The main reason for this is that they are exposed to rain, wind, or sun all through the day. Even if the window sill gets a little wet and stays that way for a long time, it turns into a fungus habitat.

All these fungi are responsible for rotting the sill. A rotten sill in the house looks bad.  In case you have wooden windows, you have no choice but to replace rotten sills to prevent your windows from getting affected by fungi. Instead of changing or replacing the entire window, you can opt to replace just the sill which will solve your predicament.

Prior to starting the replacement process, gather all the materials which have been listed below

• Measuring tape
• Lumber
• Pliers
• Wrenches
• Finish nails
• Pry bars
• Wood putty
• Saber saw
• Hammer

Before you start to replace a rotten window sill, use the measuring tape to measure the length, thickness, and breadth of the window sill.

You will have to take out the sash channel trim along with all its side pieces to get to the sill. It you face a difficulty in removing any trim, use a pry bar to loosen and then take it out. After your work with the pry bar is done, keep it away so that is does not interfere while you remove other trims.

Pull out any nails remaining in the wall or window frame. You can do this with the help of pliers or wrenches. Also, remove the nails from the trim, by pulling them from the rear side.

Once you have removed all the nails, hold the sill and pull it out carefully. Do not damage or brake the sill as you would require it as a benchmark for fixing the new window sill. Bring the old sill to a local home improvement store, and buy lumber. Also purchase nails (6d or 8d), which you would require to install the new sill.

The measurements you took in the first step will come in handy now, as you will have to do markings on the lumber. If you find it difficult, them simply trace the outline of your old sill on the lumber.

Use a saw to cut out a new sill from the lumber. You can smooth out its edges by using a fine blade. The end grain cuts will require some sanding. Use a pair of gloves while doing this step, so that, you do not get any splinters under your nails or on your hands.

Fix the new window sill where you want to and hammer in a couple of nails so that it stays in position. Also hammer a couple of nails at places from where you removed the trim. Take a perspective at the sill to determine whether it is in the same position as you wanted it to be. After verification, nail all other pieces firmly.

All nail holes need to be filled with wood putty. You can then paint or decorate the new sill to match your home decor.

You may find it difficult to perform this procedure if you are uncomfortable working with hand tools. In such a case, do not try to attempt this process, as you could cause unnecessary damage to your windows or the frame. You can always call a professional carpenter to help you in replacing window sills.