Somebody comes to look at a front door that is sticking, draughty and looking tired, and leaves two quotes: one to fix it, one to replace it. The fix is cheaper today. The replacement is supposed to be better. Neither number tells you which one is the right call, because the real question is not cost — it is whether the thing that failed is repairable in principle.

Some door faults are maintenance items that will keep being maintenance items for another twenty years. Others are the visible end of a problem that repair can only postpone. Here is how to tell which one is in front of you.

Start with what actually failed

An entrance door is four separate systems that happen to be sold together: the slab, the frame, the hardware and the weather seal. They fail independently, they have very different service lives, and three of the four can be dealt with without touching the others.

So the first question is never “is this door old?” It is “which of the four is the problem?”

Hardware — almost always repair

Locks, latches, handles, hinges, multipoint gearboxes, closers. These are consumable. They wear out, they are designed to be replaced, and replacing them on a sound door is routine. A door that will not lock is rarely a door problem.

Weather seal — almost always repair

Weatherstrip takes a compression set over years and stops sealing; sweeps wear through at the threshold; thresholds themselves can usually be adjusted or swapped. A draughty door is the single most common reason people decide they need a new one, and it is the least likely to require it.

Frame — depends entirely on where the damage is

Surface rot at the base of a jamb, a spread frame after a break-in, or a brickmould that has let go are all repairable. What is not straightforwardly repairable is a frame that has lost its structural anchoring, or one where rot has reached the sill and the framing behind it. At that point you are rebuilding the opening, and the slab is a detail.

Slab — the one that decides it

This is where the replace answer usually comes from, and specifically from three conditions: a slab that has warped or twisted enough that no hinge or strike adjustment brings it back into plane; a hollow steel or fiberglass slab where the core has taken on water and delaminated; and a wood slab with joint separation through the rails. Each of those is a change in the shape or integrity of the door itself, and you cannot adjust your way out of a shape problem.

A visit that actually identifies which of the four failed is worth more than either quote, and it is the normal starting point for residential door repair work.

Five checks that tell you which side of the line you are on

1. Is the gap around the slab even?

Close the door and look at the reveal — the gap between slab and frame — along the top, the latch side and the hinge side. A consistent gap means the door and frame are still in agreement, and whatever is wrong is adjustable. A gap that is tight at one corner and wide at the diagonally opposite one means either the frame has racked or the slab has twisted, and the next check separates those.

2. Does the slab sit flat against the stop?

Close the door and look along the stop from the side, at eye level. If the slab touches the weatherstrip at the top and bottom but stands off in the middle, or vice versa, the slab is bowed. A bowed slab is a replacement conversation. A frame out of square while the slab is still flat is a frame repair.

3. Press the bottom few inches of the slab

On a steel or fiberglass door, press firmly at the bottom rail and at the bottom corners. Sound material feels rigid. Delaminated material feels soft, slightly spongy, or moves independently of the skin. That softness is water in the core, and it does not dry out or come back. It is the clearest single indicator that a slab is finished.

4. Check the hinge screws

Open the door and lift the outer edge slightly. Movement at the hinges usually means screws have lost their bite in the jamb rather than anything wrong with the door. This is one of the most common causes of a dragging or non-latching door and one of the cheapest to correct.

5. Look at the sill and the sub-sill

Probe the sill at each end with something blunt. Soft wood at the sill ends means water has been getting past the threshold for a while, and the framing under it needs looking at. This is the check people skip, and it is the one that most often changes the answer — because a new door set onto a compromised sill will fail the same way.

When replacement is genuinely the better economics

Three situations, none of them about age on its own.

The repairs stack. One item is a repair. Slab bowed, sill soft, frame racked and hardware worn, all at once, is a replacement — not because any single item is fatal but because you would be paying labour four times on the same opening.

The opening is being changed anyway. If the entrance is being widened, a sidelight added or removed, or the surround rebuilt, the door goes in as part of that work at a fraction of what it would cost as its own project later. Entrance door replacement planned alongside other work is much less disruptive than the same job done twice.

The door is a security problem you cannot fix. A slab that has been forced and is no longer sound around the lock area, a frame with no reinforcement at the strike, or a hollow slab with a compromised lock edge cannot be hardened back to where it was. Better hardware in a weak door does not make a strong entrance.

When repair is clearly right, even on an old door

If the slab is flat and sound, the frame is anchored, and the sill is dry, then almost everything else is service work — regardless of whether the door is five years old or forty. A solid old door with worn hardware, tired weatherstrip and a sagging hinge is a good door having a bad decade. A Toronto door repair visit on a door like that typically resolves the complaint and buys years, and it is the answer a great many replacement quotes are quietly competing with.

Frequently asked questions

Is there an age at which a door should just be replaced?

No. Condition and construction decide it. A well-built solid door that has been maintained can outlast two cheap replacements, and a poorly made door can be finished in under a decade.

My door is draughty. Doesn’t that mean it has failed?

Usually it means the seal has failed, which is a different part. Weatherstrip, sweep and threshold are serviceable items. Check those before accepting that the door itself is the cause.

Can a warped door be straightened?

Rarely, and rarely permanently. Some minor bow can be compensated for with hinge and strike adjustment, but a slab that has twisted has changed shape and generally will not hold a correction.

If only the slab is bad, can the frame stay?

Often yes, and it is the less disruptive route — provided the frame is square and sound and the new slab matches the hinge and lock prep. A slab-only change avoids touching the interior trim and the exterior cladding.

What about the glass in the door?

A failed sealed unit in a door light is usually replaceable on its own. Fogging between panes is a seal failure, not a door failure, and it does not mean the slab needs to go.