Roof Replacement in Mercersburg, PA

Mercersburg has 859 homes, and half of them were standing by 1942. Below: what the code asks of a replacement here, the permit, and the town’s own records.

New Roofing Costs connects homeowners with independent local roofing contractors. We do not perform roofing work.

Call (833) 781-1806 Replacement and new roofs only · homeowners

This number connects homeowners who are planning a new roof or a full roof replacement with independent local roofing contractors. It is not for leak repairs or patch jobs. The call must come from the homeowner who decides on the roof. Calls may be recorded.

A Pennsylvania stone-and-brick house with a new shingle roof

The rules for a reroof in Mercersburg

Permit

Ask Mercersburg first

The state code does not cover a reroof that changes no structure (34 Pa. Code § 403.1(b)(8)). So the borough code office in Mercersburg is the one to ask before work starts.

Source: 34 Pa. Code § 403.1(b)

Layers

Two layers means a tear-off

On a roof that already carries two layers, or slate or tile, the code allows no recover: it is a tear-off (IRC R908.3.1.1). 79% of Mercersburg’s homes were built before 1980; many have been reroofed before.

Source: IRC 2021, Chapter 9 (Pennsylvania edition, UpCodes)

Ice barrier

Set by the local climate table

Whether an eave membrane is a code item depends on the climate table the municipality filled in when it adopted the code (IRC R905.1.2, Table R301.2). The contractor or the borough code office in Mercersburg will know.

Source: IRC 2021, Chapter 9 (Pennsylvania edition, UpCodes)

Checked against the code text on October 24, 2026. Code edition, permit and contract rules for the whole state: roof replacement in Pennsylvania.

Homes and roofs in Mercersburg

58% of the occupied homes in Mercersburg are lived in by their owners: 456 households, the people this line is for. Counting by decade, 49% before 1940, 62% before 1960, 79% before 1980 of the housing was in place, and 7% dates from 2000 on. (ACS 2020–2024.)

The housing is 59% detached houses, 12% attached single-family houses (rowhouses, twins and townhouses), 15% buildings of two to four units.

Older houses hide their history: ask the contractor to confirm the deck (board or sheet) and every layer above it before pricing, because slate or two layers mean a full tear-off.

Of the 20 Franklin County municipalities on this site, Mercersburg has the 2nd largest share of homes built before 1980: 79%, against a county range of 38% to 80%.

Mercersburg and the towns around it

Place	Median built	Before 1980	Owners	Row, twin	Hail days
Mercersburg	1942	79%	58%	12%	9
Peters	1974	57%	90%	2%	7
Montgomery Township, Franklin County	1980	51%	83%	6%	12
St. Thomas	1976	60%	84%	0%	7
Greencastle	1968	61%	62%	8%	12
Antrim	1985	46%	89%	8%	14

Median built: median year the homes were built. Before 1980: share of homes built then. Owners: share of homes that are owner-occupied. Row, twin: share of homes that are rowhouses, twins or townhouses. Census ACS 2020–2024. Hail days: days with hail of 1 inch or larger within 10 miles, 2006–2025, NOAA Storm Prediction Center.

Hail and storms near Mercersburg

Since 2006 the National Weather Service has logged hail of 1 inch or larger on 9 separate days within 10 miles of Mercersburg; the largest was 2 in on May 26, 2011. The most recent was August 7, 2023.

At the county level, Mercersburg shares Franklin County’s record of 4 storm disaster declarations since 2006, the newest DR-4267 (Severe Winter Storm and Snowstorm, March 2016). (OpenFEMA.)

Storm reports are what observers logged, not a measure of damage to any roof. When wind or hail damage means a new roof.

What goes on the roof next

HUD’s useful-life figures are for planning; a warranty is a separate promise. For Mercersburg’s houses: More in the guides to shingles, metal, slate and flat roofs.

Material	HUD useful life	Fits a house like	Watch for
Asphalt shingles	20 years	Most pitched roofs; 59% of homes here are detached	Wind class set by the design wind speed (IRC Table R905.2.4.1)
Metal (standing seam, panels)	50 years	Low pitches and long runs	A complete standing-seam system may go over the old roof (R908.3.1)
Slate	75 years	Older houses; 49% here predate 1940	Can’t be roofed over; check the framing for the weight
Flat roof: EPDM or TPO	15 years	Additions and porch roofs	Where the roof meets a wall or parapet

Checking a contractor in Pennsylvania

Pennsylvania’s home improvement law (HICPA § 3, § 6) requires registration with the Attorney General from $5,000 a year of such work and puts the number on every estimate; ask for it in Mercersburg and look it up.

Contracts, deposits and the right to cancel: checking a roofing contractor. What moves the price: new roof cost in Pennsylvania.

Questions about a new roof in Mercersburg

Do I need a permit to replace a roof in Mercersburg?

Ask Mercersburg first. The state code does not cover a reroof that changes no structure (34 Pa. Code § 403.1(b)(8)). So the borough code office in Mercersburg is the one to ask before work starts.

Can a new roof go over the old one in Mercersburg?

When were most homes in Mercersburg built?

By the Census Bureau’s American Community Survey (2020–2024), the median home in Mercersburg was built in 1942, 79% of homes were built before 1980, 58% are owner-occupied.

How often does hail hit Mercersburg?

Hail of 1 inch or larger was reported on 9 days within 10 miles of Mercersburg from 2006 through 2025 (NOAA Storm Prediction Center). A report means hail fell nearby, not that a roof was damaged.

What license or registration should a roofer in Mercersburg have?

What they will ask on the phone

Your address or ZIP code in Mercersburg
How many stories the house has, and whether it is detached or attached
What covers the roof now and about when it went on
Whether there is one layer or more, if you know
That the job is a full replacement or a new roof, and your timing
Whether the house is in a historic district or an HOA
That you own the home and decide on the roof

The full list: before you call.