Exterior door replacement on Cape Cod is mostly a rot and water job that ends with a new door in the opening. The door itself takes an hour to hang. The day goes into what we find once the old unit comes out: a jamb leg that is soft at the bottom, a sill sitting on bare subfloor, shingles that were never flashed to the frame, and a strike plate that someone has moved three times trying to make the door latch in August. Fix those and the new door works for decades. Skip them and a brand new door drags, leaks and swells exactly like the old one.
Coast Carpentry Home Group replaces exterior doors on Cape Cod homes, front entries, side and basement doors, sliders and hinged patio doors, as part of our door and window installation on Cape Cod, from our shop at 14 Parker Rd, Unit A in Osterville. Our carpenters do the whole opening: the rot repair, the sill pan, the flashing into the cedar shingles and the trim, not only the hanging. This is how we approach a door on a Cape house, what salt air does to each material, and the handful of code and town rules that catch homeowners by surprise.
Key takeaways
- On Capes and ranches built from the 1950s through the 1980s the exterior door sill often sits directly on the subfloor with no pan under it, so the rot is usually in the jamb legs and the rough sill, not the door. We rebuild that framing before the new unit goes in.
- Within sight of salt water fiberglass outlasts steel. Steel doors rust from the bottom rail up once the salt finds a chip in the finish. Wood still works under a deep overhang if the owner is willing to keep a finish on it.
- A door that latches in January and sticks in August is swelling with humidity. A new prehung unit with an adjustable threshold, an adjustable strike and three inch hinge screws into the framing holds its fit through both.
- Every door we set goes in over a sloped sill pan with a back dam, with flashing tape lapped into the water barrier and a head flashing above the trim, and the white cedar shingles are cut back and rewoven to the new casing.
- Massachusetts requires one exterior door with a clear opening of at least 32 inches wide and a landing on both sides, and a front door visible from the street in the Old King’s Highway district needs the committee’s sign off before it changes.
Why do exterior doors fail faster on Cape Cod than they do inland?
A door on a house in Yarmouth Port or Woods Hole lives in a different climate from the same door in central Massachusetts. The salt haze that settles on cars overnight settles on the door hardware too, and anything plated or painted over steel starts pitting within a few seasons. We see it first on the bottom rail of steel doors and on the hinge knuckles, then on the strike plate and the kick plate screws.
Rain on the Cape rarely falls straight down. A nor’easter drives it sideways against the windward face of the house for a day or more, and a door that only has a bead of caulk between the brickmould and the shingles takes water behind the casing every storm. That water runs down the jamb, pools on the sill and soaks the subfloor under it. Nobody sees it until the bottom of the jamb goes soft or the floor inside the door gets spongy. Our guide to storm damage siding repair on Cape Cod covers the same problem on the wall around the door.
Then there is humidity. From late June through September the air on the Cape is saturated, and a wood door, especially an older one with only paint on the face and nothing on the top and bottom edges, picks up moisture and grows. By January the furnace has dried it back out and the weatherstrip no longer touches. People plane the door in August and shim the strike in January and the door never fits in either season.
How do we tell whether the door needs replacing or the jamb needs rebuilding?
Most of the houses we work on in Hyannis, Centerville and West Yarmouth were built when a door sill was set straight on the plywood with a bead of caulk, if that. Forty years of water running down the jamb ends up in the subfloor and sometimes the rim joist. When the awl goes into the rough sill, the job becomes carpentry first: we cut back the rotted subfloor and sill, sister or replace the rim where it is punky, treat the new wood and then build the opening back to square. We have opened doors in Dennis where the only thing holding the threshold up was the interior flooring.
This is also where we tell some homeowners not to replace the door. A wood door that sticks in August and fits in January is a finish problem, not a door problem. Seal the top and bottom edges, which almost nobody paints, adjust the strike once, and it will behave. A draft at the bottom is usually a worn sweep or a threshold cap that has never been raised. A door that sags and catches the strike on the latch side often needs one three inch screw through the top hinge into the jack stud. We would rather spend an hour on a repair than sell a door that was not the problem. Our older post on why door installation matters for heat loss goes deeper on the draft side of it.
Slab, insert or full frame: which replacement fits an old Cape house?
A slab swap is tempting because it is quick and the trim stays put. The catch on a Cape house is that the old frame is almost always the thing that failed. If the jamb is out of square, the new slab has to be fitted to a crooked opening and you have bought a new door that still binds. If the old sill has no pan under it, the new slab leaks exactly where the old one did. We do slab replacements on doors we installed ourselves or on frames we can prove are sound and flashed, and not many others.
A full frame prehung unit comes as the door, the jamb, the threshold and the weatherstrip built as one piece in a factory. We pull the old unit back to the rough opening, repair whatever framing needs it, set a pan, and hang the new unit plumb and square against new framing. The trim gets replaced inside and out, which is extra work but also the only way to get the flashing right behind it. On a 1960s Cape in Sandwich or Falmouth this is the honest replacement. Our trim carpentry crews do the casing so the new door looks like it was always there.
Which door material holds up near salt water: fiberglass, wood or steel?
| Material | How it behaves in Cape salt air | Where we use it |
|---|---|---|
| Fiberglass | Stable through the humidity swing, no rust, no rot, holds a factory or field paint finish. Smooth or wood grain skins. Dark colors in full sun need a finish rated for it. | Most front, side and patio doors, and every door on a waterfront or windward exposure. |
| Wood | The classic Cape look, and it moves with the seasons. Needs the top and bottom edges sealed and a fresh finish every few years. Rots at the bottom rail when the finish fails. | Covered entries on older homes in Barnstable Village, Sandwich and the historic districts where the look matters. |
| Steel | Strong and inexpensive, but one chip in the finish and the salt starts the rust. Bottom rails and hinge edges go first, and dents do not repair cleanly. | Inland utility and garage service doors away from the water. Not on the shore. |
For patio and entry doors we install Andersen, and for the doors that face the water we specify the fiberglass options and stainless or lifetime finish hardware. Our earlier post on picking materials for a Cape Cod door installation walks through the style side of that choice. The short version from the install side is that the material has to survive the sill, not just the showroom. A beautiful wood door set on a pan, under a roof, with its edges sealed, lasts a very long time here. The same door on a south facing wall in Mashpee with no overhang is a maintenance plan.
How do we flash a new door into white cedar shingle siding?
The sill pan is the part that matters most and the part that is missing from almost every door we take out. It is a formed or flexible pan that catches any water that gets past the door, slopes it back outside and has a raised lip on the inside edge so it cannot run onto the subfloor. We bed the threshold on it in sealant at the front and leave the back open so the pan can drain. A door set this way can leak at the weatherstrip during a storm and still keep the floor dry.
At the sides and top the rule is the same one that governs everything on a shingled wall: each layer laps over the one below it so water always runs out, never in. Flashing tape goes over the jamb flange and under the housewrap, and a bent metal head flashing sits over the head casing with its upper leg tucked under the wrap above. Caulk is the last line, not the first. The white cedar shingles around the opening get cut back cleanly, and new shingles are woven in to meet the casing with a small gap off the head flashing so the bottom course can dry. Done right, the new door looks like it grew there and the wall sheds water the way it did before anyone touched it.
Should a Cape Cod front door swing in or out, and is a storm door worth it?
Inswing is the default and for good reason: it lets you fit a storm door, it keeps the hinges inside, and it is what the opening was built for. We switch to outswing on doors that get hammered, a side door facing Nantucket Sound in Popponesset or a bayside entry in Barnstable Village. Wind pressure on an inswing door pulls it away from the weatherstrip; on an outswing door the same gust presses it tighter. Outswing units get hinges with non removable pins or a security stud so the exposed hinges are not a weak point, and we check the landing so the door is not swinging out over a step down.
Storm doors earn their keep on a door that faces the weather. They take the rain and the wind instead of the main door and add a dead air space that cuts the draft. The catch is heat. A full glass storm door in front of a dark fiberglass or steel door on a south or west wall traps enough sun to blister the finish and warp the slab, and door manufacturers say so in their warranties. On those exposures we either go with a lighter color, a vented storm door or no storm door at all and a better overhang. On the north and east sides of the house a storm door is nearly always a good idea.
Why does a Cape door stop latching in August, and how do we build one that does not?
The latch problem is really two problems. The first is the door and frame changing size with the seasons, which is why we steer most Cape entries to fiberglass and why wood doors get every edge sealed before they go in. The second is the frame moving in the opening. A jamb held only by finish nails through the casing walks over time, especially when the hinge side carries a heavy door. We shim behind every hinge and behind the strike, then run long screws through the jamb and shims into the jack stud, and we replace at least one short screw in each hinge with a three inch screw. The door hangs from the house, not from the trim.
Then we set the adjustments. Modern units have an adjustable strike plate and a threshold cap that raises and lowers, and the right time to set them is spring or fall when the door is at its middle size. We set the strike so the door closes with light pressure and the weatherstrip compresses evenly top to bottom, and we show the owner the two screws that move the threshold cap so a draft in January is a thirty second fix, not a service call. Hardware is the last piece. On the shore we use stainless steel ball bearing hinges and lock sets with a marine grade or lifetime finish, because a bright brass handle set two streets from the water is pitted by the second summer.
What do Massachusetts code and the Cape towns require for a replacement door?
The egress door rule is the one that changes the plan on older cottages. If the only side hinged door on the house is a 30 inch door, a like for like replacement does not meet the code, and the fix is widening the opening with a new header, which is a permit and a day of framing. A standard 36 by 80 inch unit gives you the clear opening the code asks for with room to spare. The landing rule matters on back and side doors that open onto a single step: the code wants a landing as wide as the door and 36 inches deep, and on the required egress door the exterior landing can sit no more than one riser below the threshold when the door swings in. The Barnstable Building Division and the other town building departments will tell you in one call whether your swap counts as an ordinary repair or needs a permit. When it needs one, we pull it under the Construction Supervisor license Fagner Rodrigues holds.
North of the Mid Cape Highway, in Sandwich, Barnstable, Yarmouth, Dennis, Brewster and Orleans, a front door visible from the street falls under the Old King’s Highway Regional Historic District. A door that matches the existing one in size, style and material can usually go through as an exemption; a change in style, glass or color goes to the committee for a certificate of appropriateness, and that meeting schedule becomes part of the job timeline. We have done both and build the review into the schedule rather than finding out at inspection. Conservation review almost never touches a door replacement unless the landing or steps are being rebuilt inside the wetland buffer.
How long does an exterior door replacement take on Cape Cod?
We measure the rough opening, the wall thickness and the swing before anything is ordered, because a Cape wall with two layers of siding and a plaster interior is thicker than a stock jamb and needs an extended jamb or a jamb extension milled on site. We replace one door at a time so the house is never open overnight, which is also how we work in winter: an opening is out and the new unit is in and weathertight the same day, with the interior trim finished after. Owners who want a door before summer should be ordering in late winter, because lead times stretch when every contractor on the Cape is ordering at once in April.
What drives the cost of exterior door replacement on Cape Cod?
Two identical doors on two identical Capes can be very different jobs, because one opening is sound and the other has a rotted rim joist under the sill. That is why we do not quote door replacement from a photo and why we do not publish a per door figure. What we do promise is that the estimate names each of those items so you can see what is door and what is repair, and that the work carries our lifetime workmanship warranty. If something we installed is wrong because of how we installed it, we come back and fix it at no cost; the door itself carries its manufacturer’s warranty. With more than 25 years of experience on Cape houses, we would rather tell you the frame needs rebuilding than hang a new door on a rotted sill and let you find out next winter.
Start with the opening, not the catalog
Coast Carpentry Home Group replaces front, side, basement and patio doors across Cape Cod, from Falmouth and Mashpee through Osterville, Hyannis, Barnstable, Sandwich, Yarmouth and Dennis, as part of our door and window services. Our carpenters handle the rot repair, the sill pan, the flashing into the cedar shingles and the trim, so the whole opening is one job by one crew. Request a door replacement estimate, or read what Cape homeowners say about our work on our reviews page. If the door is part of a bigger refresh, our guide to exterior remodeling on Cape Cod shows where it fits in the order of work.
Frequently asked questions
Can you replace an exterior door without replacing the frame?
Yes, when the frame is square, solid at the bottom of both jamb legs and sitting on a sill pan. We check all three with a level and an awl before agreeing to a slab only replacement. On most Cape doors over twenty years old at least one of those fails, usually the pan, which was never there, and a full frame unit is the repair that actually solves the leak and the binding.
Do I need a permit to replace an exterior door in Massachusetts?
A same size replacement in the existing opening is often treated as an ordinary repair, but the towns on the Cape do not all draw that line in the same place, so we confirm it with the building department for each job. Anything that changes the opening, the header, the landing or the only egress door needs a permit, and a street facing door in the Old King’s Highway district needs the historic committee’s approval as well. We handle the paperwork either way.
Is a steel door a bad idea near the ocean on Cape Cod?
Within sight of salt water, yes. A steel door is only as good as its paint, and the first chip at the bottom rail or a hinge edge lets salt start rust that works under the finish. We take out steel doors in Hyannis Port and Falmouth Heights that are rusted through at the bottom after ten or fifteen years. Fiberglass costs more up front and is the door we recommend on any shore or windward exposure.
Why does my new door still let in a draft at the bottom?
Almost always because the adjustable threshold cap was left at its factory setting. Most new units have a cap that raises with two or three screws from the top; it should be set so a sheet of paper drags lightly when the door is closed. If the gap is at one end only, the threshold is not level or the door slab is out of square in the frame, which is an installation problem and not something the sweep can fix. Check the sweep itself last, since a torn sweep shows up as a draft the full width of the door.
Can an exterior door be replaced in winter on Cape Cod?
Yes. We do it one opening at a time so the house is never open overnight. The old unit comes out in the morning, the framing repair and pan go in, and the new unit is set, foamed and weathertight by afternoon. Interior trim and paint can follow on a warmer day. Low expansion foam and sealants have temperature limits, so on the coldest days we warm the opening and the materials, and on a windy day we hang a tarp on the inside to keep the house comfortable while the door is out.
We serve Cape Cod, Massachusetts
Coast Carpentry Home Group works across all 15 Cape Cod towns, from Bourne out to Provincetown. We do not take projects outside the Cape.
On the Cape and looking for an estimate? Call (508) 360-9658 or send us a message.
Time to upgrade drafty doors or windows?
Coast Carpentry Home Group provides door and window installation on Cape Cod. Licensed, insured, and local, with 25+ years of experience. Call (508) 360-9658 for a free estimate.