The code your stucco was supposed to be built to

This page exists because almost everything written about stucco remediation locally is adjectives. The requirements below are not opinions and they are not ours — they are the code, quoted, with the source named so you can check every one.

Which code applies in Pennsylvania

Pennsylvania regulates residential construction through the Uniform Construction Code, administered by the Department of Labor and Industry, which adopts the International Code Council's model codes with amendments. The UCC Review and Advisory Council completed its review of the 2018 I-Codes in April 2021, and the 2018 International Residential Code was adopted by regulation on 14 February 2022, taking effect immediately. Individual municipalities enforce it through their own code offices — Bucks County has no county-wide residential building department.

That date matters for a different reason than most people assume. It does not tell you what your house was built to. A home built in 1998 was built under whichever code edition its municipality had adopted then, and enforcement of the flashing and drainage details below was inconsistent across exactly the period Central Bucks was being developed. The current code tells you what good looks like; it does not tell you what you have.

1. The water-resistive barrier — two layers, not one

On wood-based sheathing, the code requires a water-resistive vapour-permeable barrier "with a performance at least equivalent to two layers of Grade D paper", and it is specific about how: "the individual layers shall be installed independently such that each layer provides a separate continuous plane, and any flashing intended to drain to the water-resistive barrier is directed between the layers."

There is an exception where the barrier over wood-based sheathing performs at or above 60-minute Grade D paper and is separated from the stucco by an intervening, substantially non-water-absorbing layer or a designed drainage space.

Why two. This is the part worth understanding, because it explains the whole failure mode. Stucco is cementitious and therefore alkaline, and it degrades paper fibre over time. The outer layer is sacrificial: it takes the alkali attack so the inner layer survives to keep doing its job. A wall built with one layer has a barrier with a service life, not a permanent one — and a wall built with two layers bonded together rather than as two independent planes has no drainage path between them, which is functionally the same as having one.

2. The weep screed — and the four inches almost nobody has

The code requires a corrosion-resistant weep screed with weep holes at the foundation plate line, minimum 0.019 inch thick (No. 26 galvanised sheet gauge), "placed not less than 4 inches above the earth or 2 inches above paved areas and of a type that will allow trapped water to drain to the exterior of the building."

This is the single easiest thing for a homeowner to check without tools. Walk the base of the wall. You are looking for a metal edge with holes in it, with visible clearance above the soil, the mulch, the patio or the driveway. If the stucco runs straight into the ground, the wall has no way to drain at the bottom and is wicking ground moisture upward.

Worth knowing: a weep screed that was compliant when built can be made non-compliant afterwards by landscaping. Beds raised against the wall, mulch topped up year after year, or a patio poured to the stucco all bury the screed and defeat it. That one is fixable in an afternoon.

3. Roof-wall flashing — the detail the code describes but never names

The roofing provisions require that "flashings shall be installed at wall and roof intersections, wherever there is a change in roof slope or direction and around roof openings", and specifically that "a flashing shall be installed to divert the water away from where the eave of a sloped roof intersects a vertical sidewall". Metal flashing must be corrosion-resistant and not less than 0.019 inch thick.

That last sentence is the requirement everyone calls kickout flashing. Here is the detail that tells you whether someone has read the code or is repeating what they heard: the IRC does not use the term "kickout flashing" anywhere. It describes the function — divert the water away — and leaves the name to the trade. Some states have written the term into their own amendments; the model code has not.

It is also the most damaging omission in this county, because of arithmetic rather than severity. Without it, an entire roof plane's runoff is delivered behind the cladding at one point a few inches wide, every time it rains, for as long as the house stands.

A note on section numbers

You will see these requirements cited as R703.6.x in some places and R703.7.x in others, and both can be correct: the exterior plaster provisions were renumbered between IRC editions, so the citation depends on which book the writer had open. Pennsylvania is currently on the 2018 edition. The substance of the three requirements above has been stable across editions, which is why this page quotes the requirement rather than leading with a number. If a contractor cites you a section, the useful question is which edition they are citing — not whether the number matches something you read elsewhere.

What the moisture reading means

An invasive inspection reports moisture content as a percentage of the wood's dry weight. Wood in a wall assembly normally sits below about 15%. Sustained readings at or above roughly 20% are the conditions under which fungal decay proceeds — which is why that number, rather than any visible symptom, is what decides between a repair and a remediation. Readings between about 16% and 19% are elevated and worth re-testing rather than acting on immediately.

Who is allowed to do the work

Pennsylvania's Home Improvement Consumer Protection Act requires anyone performing more than $5,000 of home improvement work in a year to register with the Office of Attorney General. Registrants must carry at least $50,000 in general liability coverage, and the registration number must appear on all contracts, estimates, bids and advertising — including digital. Initial registration and biennial renewal are $50 each.

Two practical consequences. First, a stucco contractor whose PA number is not on their estimate is not complying with the statute, which tells you something before you check anything else. Second, the register is public: you can confirm any contractor yourself at hicsearch.attorneygeneral.gov. We check it before every referral and record the date — but you should not take our word for it when the primary source takes thirty seconds.

For EIFS specifically we additionally look for manufacturer certification, because most EIFS manufacturers restrict warranty-covered work to applicators they have certified and the components are a matched proprietary set.

Where our local facts come from

The town pages on this site describe housing stock, construction era and permitting. Those come from public records, and you can check any of them:

• Build year and construction type for a specific property — Bucks County Board of Assessment property records.
• Era mix for a municipality — US Census, American Community Survey table B25034 (year structure built).
• Permitting, historic-district review and any local overlay — the municipality's own code office. Every Bucks County municipality runs its own; there is no county-wide residential building department, which is why a Doylestown mailing address tells you nothing about which office issues your permit.
• Contractor registration — the Attorney General's HIC register, linked above.

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