Door Installation Step-by-Step: What to Expect When You Hire a Handyman

Door Installation Step-by-Step: What to Expect When You Hire a Handyman

I've been installing doors in San Luis Obispo for years now—exterior doors, interior doors, sliding glass, French doors, you name it. Every single one is a little different, but the process itself follows a logic that homeowners should understand. This post walks you through what happens when you call someone like me to hang a new door.

Why You're Reading This

Maybe your back door doesn't close right anymore. Maybe you're replacing an old slider before the summer wind really picks up. Or you're just sick of the squeaky bedroom door and want something that actually latches. Whatever the reason, you need to know what to expect—timeline, decisions you'll make, potential surprises, and how the work actually gets done.

Step 1: The Free Estimate

You call. I show up, usually within 24 hours. I bring my tape measure and I look at what you've got.

I'm measuring the rough opening (the hole in the wall), checking if the jambs are plumb and square, looking at the floor condition, and honestly assessing whether this is a straightforward swap or if there's hidden damage underneath. This is where I earn trust. If there's water damage in the header from coastal humidity or salt air—common around here—I'm telling you about it now, not discovering it halfway through the job.

I'll ask you about:

Willy doesn't rush this part. Questions answered, estimate given, no surprises later.

What You Need to Decide Before I Arrive

Don't make me guess. Know whether you want:

The door material. Fiberglass exterior doors handle our coastal salt air better than solid wood without ongoing maintenance. Interior doors are simpler—hollow core for closets, solid core if you want sound dampening. I've installed plenty of both in homes from Paso Robles down to Nipomo.

Left or right swing. Stand outside the door opening facing inward. If the hinges go on your left side, that's a left-hand door. This matters. Get it wrong and the door swings the opposite direction.

Pre-hung or slab. A pre-hung door comes already mounted in its frame. A slab is just the door itself—you install it on existing hinges. Pre-hung is easier for me, simpler for everyone. But if your opening is an odd size or you're replacing just the door on the existing frame, a slab makes sense.

Step 2: Removing the Old Door (If There Is One)

First thing I do is protect your flooring. Drop cloths, tape on the carpet if needed. This job creates dust and debris.

Then I unscrew the hinges—usually three per door. On exterior doors, I'm checking the condition of the jambs and sill while the door's off. If there's rot (I've found plenty in older SLO County homes where the doors face northwest and get soaked by the marine layer), we talk about whether to sister in new wood or replace the whole frame. This changes the scope of work, and I tell you straight.

I'll also remove the old hardware—lockset, deadbolt, threshold if it's exterior—and set it aside. Sometimes you want to keep it; usually it goes in the trash.

Step 3: Preparing the Opening

This is where Willy gets detailed.

I check the rough opening with a level on all four sides. Exterior doors especially need the sill sloped slightly outward so water sheds away from the house. If the opening's out of square by more than 1/4 inch, I'm shimming and adjusting before the new door goes in.

For exterior doors, I'm sealing any gaps in the framing with caulk or expanding foam, depending on the gap size. Our dry summers on the Central Coast mean moisture isn't the issue right now—but interior temperature swings mean air leakage is. Getting this tight matters.

I also check under the sill. If there's any soft spot (evidence of old water damage), I'm treating it or replacing it before the new door sits on top of it.

Step 4: Installing the New Door

Here's where it all comes together.

For a pre-hung door, I'm setting the frame into the opening. I use shims—little wooden wedges—to get the frame perfectly plumb and square. Not eyeballed. Checked with a level and a square. This is non-negotiable. A door that's even slightly crooked will bind, won't close right, and will frustrate you for years.

Once it's positioned, I drive fasteners through the jambs into the framing. For exterior doors, I use stainless steel fasteners; we're close enough to the ocean that regular steel will corrode. Interior doors get standard screws.

Then I check the reveal—the gap between the door edge and the jamb on both sides. It should be consistent top to bottom. If it's not, the door won't swing freely.

For a slab door (just the door, no frame), I'm hanging it on existing hinges or installing new ones, then adjusting the hinges so the door hangs square in the opening.

The Truth About Getting It Right

I've walked away from a job site five years later and seen a door I installed that still closes smooth as butter. I've also seen somebody cut corners early and watched that same homeowner deal with a binding door that won't latch. There's no middle ground on this one. You do it right the first time.

Step 5: Sealing (Exterior Doors)

After the door's hung, I seal around the exterior frame. Exterior-grade caulk on all sides where the frame meets the wall. I'm filling shim gaps too.

On the bottom, if there's a threshold, I'm making sure water can't pool. If you're going without a threshold (which is fine for certain styles), I'm sloping that sill and sealing the underside of the frame so water runs away from the house.

Don't skip this step. Water getting behind an exterior door frame is a slow-moving disaster that won't show up for a year or two, then suddenly you've got structural damage and a much bigger project on your hands.

Step 6: Hardware Installation

This is the handset—the lockset and deadbolt. If the door came pre-bored, I'm just installing the hardware into existing holes. If not, I'm drilling and chiseling for the strike box, mortising the hinges if needed, and making sure the lock actually latches and the door actually deadbolts.

Small details matter. A lockset that doesn't seat flush, a deadbolt that doesn't retract smoothly—these are signs the door or frame isn't quite square. We fix it now.

Step 7: Final Adjustments and Testing

Open and close the door 20 times. I'm listening for binding, checking that it latches every time, making sure the deadbolt works smooth, and verifying the door doesn't swing open on its own (a sign the frame is twisted).

For exterior doors, I'm testing weather stripping—it should compress when the door closes and seal all the way around.

Then I clean up. Tools, debris, packaging material—it all comes with me.

Common Problems I Find Mid-Job

Out-of-square openings. Clay-rich soil on the Central Coast settles unevenly. Older homes shift. I've found openings that were 1/2 inch out of square. You can't force a door into that. We adjust the framing or accept that the shims will be uneven.

Hidden water damage. I had a customer in San Luis Obispo last summer with a back door that seemed fine until I removed it. The sill was soft—water had been pooling there for years. We replaced the sill and the bottom 18 inches of the frame. That's not something you see until you start working.

Existing hardware that won't match. You want the new door's lockset to match the old one. Sometimes they don't align with the new door's bores. We adapt—install what works and looks good.

Timeline

A standard door swap? Two to four hours. Pre-hung interior door, good opening, no surprises—two hours. Exterior door with frame issues, water damage, or custom hardware—four to five hours.

I schedule same-week for most jobs. Interior doors often get done the next day.

What You Should Prepare

Clear the area around the door. Move furniture, pets, anything that's in the way. If it's an exterior door, let me park close to the opening if possible. Have the new door on-site if you've picked it out, or be available to choose one when I arrive. If you're buying from a supplier, arrange delivery before the install date.

For exterior doors in our dry season, I recommend being available so I can do the work in one session—you don't want the opening exposed overnight, even in summer.

Final Word

Door installation looks simple because a door is simple. But it's one of those jobs where the difference between good work and bad work only shows up over months or years. A door that's hung right feels right—it swings easy, it latches solid, and you stop thinking about it.

That's what Willy shoots for on every job in San Luis Obispo County.

---

> Need Door Installation in San Luis Obispo? Call Willy directly.

>

> 📞 (805) 440-3887

>

> ✉️ evolutionhomeimprovement1@outlook.com

>

> 📍 1041 Southwood Dr, Ste L, San Luis Obispo, CA 93401

>

> 🕒 Monday–Saturday, 8 AM – 6 PM

>

> Free estimates within 24 hours. Same-week availability.