Installing Cedar Trim onto Brick
We were recently asked to dress up the rear entrance of the Concord Book Shop with a custom door surround. The brick surrounding this door has some sort of pink paint that the building owner wanted to hide. The ultimate goal was to create nice looking custom door surround that complimented the buildings front entrance.
I decided that I needed 8-inches in order to cover over the pink paint. The best way to accomplish this was to utilize 8-inch wide columns and a simple classic flat head entablature with crown molding. Our design was similar to a Georgian door surround but with much less detail and flat columns.
For plinth blocks we would match column block on the front of the building, matching the profile with router bits we had in our shop.
There are many commercially available products that can be ordered or custom made. We were not able to pursue those options as the local Historical District commission preferred we use real wood and not PVC. We decided to make this entire surround out of 1×4 and 2×10 cedar wood. Cedar has an inherent insect and rot resistant quality that seems to last. Plus this door surround is protected by an overhead awning.
Both the columns and header trim had to be able to cover over the PT plywood. To accomplish this we ripped 1-inch strips of cedar and glued and fashioned them to the sides of the columns, and plinth blocks and all 4-sides of the head detail.
By using a 1-inch return strip on all the custom door surround trim we would ensure some space between the PT plywood and the cedar for seasonal wood movement and to act as an air / drainage plane.
The design allows the trim to cover over the PT plywood. We then would install stainless steel trim screws, discreetly from through the side strips and into the plywood backer board.
We left the columns long and will trimmed them onsite to account for out of level grades.
We needed two plinth blocks. Originally plinth blocks were masonry support bases, but have since evolved into more of a decorative add-on for many interior decors. Plinth blocks add a touch of style and class to a room. Plinth blocks act as a decorative base for door trim, pilasters or columns. They often stand proud at the bottom of the casing. Plinth blocks also add a reveal and shadow-line depth between the vertical and base trim. Plinth blocks add a nice aesthetic detail to trim details.
We used 2×10 cedar, ripped clean, sharp edges and then glued and clamped 1-inch returns onto the block. Once the returns had dried we cut the plinth blocks to a rough size and routed a ½ round profile to the top end.
The header was designed to protrude out 1/2” on both sides of the column trim as well as the door frame. We applied 1-1/4” returns to the rear of the header trim and then applied a solid molding, similar to a crown molding detail, to the front top edge. We glued, clamped and fasted this in place.
Sanding and Priming
We filled all defect and sanded the wood thoroughly. Once done we wiped all the wood down and applied a coat of exterior primer to all sides of the wood.
In order to attach our trim to the brick we decided to mount ¾” pressure treated plywood to the three sides of the door. The plywood would be rot resistant and act as a nailer board for my trim fasteners. We started out by getting the plinth blocks to sit correctly on the door frame and be level in relation to each other. We did this with a long level, and also had to cut approx 3/8″ off one leg of each plinth block. This allowed the door side of the plinth block to overlap onto the metal door frame. This was necessary in order to have the plinth block be centered under the vertical column.
Once the plinths were cut and ready to install, we were able to place them against the wall as a dry fit. We used a long level, to plumb a reference line for the pressure treated nailer. Pre-drilling the pressure treated plywood is necessary in order to get he masonry fastener to fit. Once complete, we held the PT board on the wall reference line, and used a SDS Drill to pre-drill the mortar joints. We then installed the PT strips to the wall with expanding masonry anchors. We did this on both vertical sides of the door.
We installed pairs of masonry fasteners approximately every 16 inches.
TIP: We installed only one top, and one bottom masonry fastener and then dry fitted the vertical columns. If adjustment was needed we then tapped the PT board in the directions needed. Once perfect we installed the rest of the masonry fasteners.
Attaching the Plinth and Column Trim
We pre-drilled, and then attached the plinth blocks to the plywood nailer with 4 stainless steel screws into the face of the blocks.
For the vertical columns we dry-fit them onto the plinths to mark sure there was a tight seam. We also dry fitted the head entablature to see where it would rest, in relation to the columns. We located that mark and measured from the plinths to that mark. The columns were cut, and cut ends were primed. We also pre-drilled the return sides, attached the columns to the PT nailer and then installed fasteners into the side returns for the column.
TIP: we installed only two fasteners in the columns trim until after the entablature was installed. this was to allow for minor adjustments or easy removal if needed.
Attaching the Head Entablature
After the vertical columns were installed we measured, marked and installed an upper PT nailer. We then pre-drilled the entablature top, sides and bottom to receive fasteners. We allowed for a 1/2″ overhang left and right past the columns.
NOTE: This door surround is not flashed on top yet. our plan is to remove the grout in a joint above the head trim and install a copper flashing head.
Next we will install copper flashing into the brick mortar joint and over the head crown molding.