Window Brickmould Replacement — Rotted Exterior Window Casing
The bottom corners of the window trim are soft, the paint will not stay on, and there is a gap opening between the trim and the siding. We replace the brickmould and fix what is behind it.
Window brickmould replacement is the fix when the exterior casing around a window is soft, split or pulling away from the siding. JMB Builders pulls the rotted brickmould, checks the nailing fin and flashing behind it, tapes the jambs, adds a drip cap where one is missing, then installs new PVC or wood brickmould with glued, sealed joints. Twin Cities metro, priced per window, quoted from your photos within one business day.
- Priced per window
- Flashing and nailing fin checked before new trim goes on
- PVC or primed wood brickmould, your call
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
Brickmould is the trim that sits between the window frame and the siding. On most houses it is finger-jointed pine, and it rots from the bottom corners up. Water runs down the face, sits on the sill horn, and wicks into the end grain at the miter. Once the joint opens, water gets behind the trim and the rot spreads up the sides. It usually shows as bubbling paint, a miter that has split apart, or a screwdriver that sinks in at the bottom corner.
What matters is what is behind the trim. On a newer window there is a nailing fin and, if the installer did it right, flashing tape over the fin and a drip cap at the head. On an older window there may be nothing but the jamb and the sheathing. We do not know which until the old brickmould comes off, and that is why we look before we nail anything on.
New brickmould goes on in cellular PVC or primed wood. The head gets a drip cap kerfed or tucked under the siding, the side joints are glued, the sill horn is cut so water runs off it, and the trim is caulked to the window and the siding but left open at the bottom to drain. It goes in white or primed, filled and caulked. Painting is quoted as a separate line, or leave it primed and caulked and paint it yourself.
What you supply
- Photos: a close-up of the worst corner, the whole window from a few steps back, and one looking up under the head trim
- PVC or wood, or leave it to us and we match what is on the other windows
- Your exterior paint color if we are painting the new trim
What JMB supplies
- Removal and haul-away of the old brickmould and any rotted sill nosing behind it
- Inspection of the nailing fin, jamb and sheathing once the trim is off, with photos if anything is wrong
- Self-adhered flashing tape at the jambs and a metal drip cap at the head
- New cellular PVC or primed wood brickmould cut to match the existing profile
- PVC cement or exterior glue at the miters, stainless or coated ring-shank nails, exterior sealant at the window and siding
- Jamb or sheathing repair when the rot went past the trim, quoted from the photos before we go further
- Photos of the finished window in your job folder
- Painting the new brickmould when you want it done, quoted as its own line
How it is priced: per window
Quoted in writing from your photos within one business day. What moves the number:
- Brickmould only, or the sill nosing and jamb bottoms too
- PVC vs. wood, and whether we are matching a profile that is no longer sold
- Lap siding, stucco or brick around the window, which changes how the drip cap and side joints are done
- Whether the flashing behind the trim is missing and has to be added
- Second-story windows that need staging or a ladder setup
- How many windows in the same visit; the second window is always cheaper than the first
Push a screwdriver into the soft corner and tell us how far it goes. If it stops in the trim it is a brickmould job; if it keeps going, the jamb is involved and we quote that too.
How long it takes
One window on the first floor: a few hours. A full side of the house: about a day. Add time for jamb repair or second-story staging. Painting is quoted as its own line.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
PVC brickmould
Cellular PVC in the standard brickmould profile. It does not rot, does not need paint to survive, and takes the splash at the sill without complaint. Joints are glued with PVC cement so the miters stay closed through freeze and thaw.
Primed wood brickmould
The right choice when the house has a wood profile you want to keep, or when the trim is stained. We prime the cut ends and back-prime before it goes on, and hold it off the sill so the end grain stays dry.
Flashing found missing
The old trim comes off and there is no tape on the fin and no drip cap. We add both before the new trim goes on. It is a small addition to the job and the reason the new trim will not rot the way the old one did.
Sill nosing and jamb bottoms
The rot went past the brickmould into the wood sill nosing or the bottom of the window jamb. We cut the bad wood out square, splice in PVC or treated stock, and trim over it so the repair disappears.
Window Brickmould Replacement — Rotted Exterior Window Casing: questions, answered
What is brickmould on a window?
Brickmould is the exterior trim that covers the gap between the window frame and the siding, brick or stucco. It is usually a rounded, stepped profile about two inches wide, nailed to the window jamb and to the wall. On a house with lap siding it is what the siding butts into. When people say the window trim is rotting on the outside, brickmould is almost always what they mean.
Why is the brickmould rotting at the bottom corners of my windows?
The bottom corners are where the side pieces end in end grain and where the miter opens up first. Water runs down the face of the trim, sits on the sill, and wicks up into that end grain. Once the joint opens, water gets behind the trim and the rot climbs. If there is no drip cap at the top, water also runs behind the head piece and comes out at the bottom. Paint slows it down for a season; new trim with a drip cap, sealed joints and a drainage gap at the bottom stops it.
Should I replace rotted brickmould with PVC or wood?
For most houses we recommend PVC. Cellular PVC brickmould comes in the same profile as the pine it replaces, will not rot, and holds paint well if you want it a color other than white. Wood is the better choice when the trim is stained or when the house has a profile that is not made in PVC. Either way, the flashing behind the trim is what keeps the next set of trim dry.
Do you check the flashing when you replace exterior window casing?
Yes, every time. Once the old brickmould is off we can see the nailing fin, the jamb and the sheathing. If there is no flashing tape on the fin we add it. If there is no drip cap at the head we add one. If the sheathing is soft we show you a photo and quote the repair before going further. Putting new trim over a bare fin just moves the rot to the sheathing where you cannot see it.
Can you replace the brickmould without replacing the window?
Yes, if the window itself is sound. Brickmould is nailed to the outside of the frame and comes off without disturbing the sash or the glass. The window stays in place, the interior trim is not touched, and the new brickmould goes on the same day. If the window frame is rotted too, or the glass is fogged, we tell you, and at that point a replacement window with new trim is usually the better spend.
Does the new window brickmould come painted?
PVC goes on white and wood goes on primed, with the nail holes filled and the joints caulked. Painting is quoted as a separate line, or leave it primed and caulked and paint it yourself. If you want it painted, send your exterior trim color with the photos and we include it on the quote.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
Related jobs we do
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Read morePage reviewed September 24, 2026 · JMB Builders LLC, MN license BC809005 · All exterior trim pages
Where we work
Exterior trim near you
Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: