Adding Exterior Window Trim Over Siding

If we installed the trim after the siding we would have had to caulk a ton to fill in for the different levels the layered siding creates.

Adding exterior window trim over siding. Set the depth just deep enough to score the sheathing and the siding will come right off. Window trim is necessary to every exterior. There is no need to remove all of the siding to install the trim. Trim helps cover the edge between siding and the window frame helping to keep out the elements and protect your home.

Trim also helps complete the look of your home regardless of what it s style or the material you re siding it with. I did this on a window replacement last year. Matching black window frames with a black front door makes the beauty of natural wood siding shine. Most window trims are made from cedar or other types of wood.

Selecting the right window trim. Black exterior window trim can be made from wood metal fiberglass vinyl or other materials. Snap lines on the siding where you want to cut say 2 2 1 2 from the window and use a plywood blade backwards in a circ saw. The trick to installing exterior flat stock trim around a flanged window is having the trim sit flat in plane with the wall while the trim s outer face is proud of the siding for aesthetic reasons.

We used pressure treated 2 x 4 s for the trim around the windows and the doorway and then we had to create trim corners for both the inside and the outside corners like the ones in the picture above.