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Replace Masonite Hardboard Siding With LP SmartSide

The hardboard lap on your 1970s to 1990s house is swelling at the bottom edges, flaking and going soft.

Reply within one business day. Or call / text 763-250-3621.

To replace Masonite hardboard siding with LP SmartSide lap siding, the swollen and rotting hardboard comes off, soft sheathing is replaced, the wall is wrapped and flashed, and new SmartSide lap goes on at a reveal close to the old one, with new trim at corners and openings. JMB Builders does it across the Twin Cities and north metro. One wall or the whole house, priced per project from photos and a measure.

  • Priced per project, per wall or whole house
  • Hardboard off, sheathing checked, wall wrapped
  • LP SmartSide lap at a matching reveal
Split-level home with four new white double-hung windows set in green lap siding and brick

Hardboard siding, often called Masonite, went on a lot of Twin Cities houses from the 1970s into the 1990s. It is pressed wood fiber, and once the paint fails at the bottom edges and nail heads, it drinks water, swells, flakes and rots. The bottom course, the boards behind downspouts and the wall that gets the weather go first.

A few swollen boards can be swapped, but hardboard has not been made in the old profiles for years and patches rarely match. When rot shows on several walls, the job is replacement. LP SmartSide is an engineered wood lap that looks close to painted hardboard and comes primed; many owners pick it for that reason. Vinyl or fiber cement are the other choices, and we quote those too.

The work: hardboard off one wall at a time, the sheathing checked and soft sections replaced, house wrap and flashing at every window, door and penetration, then the new lap at a reveal close to the old one so the house keeps its look. Trim at corners, windows and doors is replaced in the same pass, since the old trim is usually hardboard too.

Get a written quote for this job

Three photos and a sentence is enough: a reply within one business day, or ask for a free in-home estimate. Or text the photos to 763-250-3621.

Photos (optional)

Up to 3: one wide shot of the area, one close-up of the opening or trim, one of anything you're unsure about.

How do you want your quote?

Free, no obligation. Every quote is written and itemized, so you can compare it line by line.

What you supply

  • Photos of each wall and close-ups of the worst boards
  • The house footprint or a rough wall-by-wall measurement; we confirm it on site
  • Your color choice: factory-finished or primed for painting
  • Whether you want one wall now or the whole house

What JMB supplies

  • Removal and haul-away of the old hardboard siding and trim
  • Sheathing repair where the hardboard let water in
  • House wrap, window and door flashing, and flashing at every penetration
  • LP SmartSide lap siding at a reveal close to the old one
  • New corner, window and door trim, and blocks for lights, hose bibs and vents
  • Clearance at roof lines, decks and grade, with kickouts where roofs meet walls
  • Painting as its own line when you want it, and photos in your job folder

How it is priced: per project

Quoted in writing from your photos, with a reply within one business day. What moves the number:

  • Wall area and number of walls
  • Sheathing rot found once the hardboard is off
  • Number of windows, doors and penetrations to flash and trim
  • One story or two, and access around decks and landscaping
  • Factory-finished versus primed siding, and painting as its own line
  • Trim replacement at corners, windows, doors and fascia

Photos of all four sides and a rough measurement get a firm quote per wall. Extra sheathing is priced per sheet on the quote.

How long it takes

One wall: one to two days. A whole one-story house: about one to two weeks depending on size, trim and weather.

How your project works

  1. 1

    Send photos, get a written quote

    Send three photos of the space and a sentence about what you want. You get a clear, itemized reply within one business day. Prefer a look in person? A free in-home estimate is always an option.

  2. 2

    Pick materials, or bring your own

    We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.

  3. 3

    Clean, precise installation

    The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.

  4. 4

    Walkthrough and invoice

    We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.

Situations and options

One wall at a time

The weather side or the back wall first, when the rest of the hardboard still has some life. The new lap is set at the same reveal so the house does not look patched from the street.

Whole house

All the hardboard off, sheathing repaired, wrapped and flashed, new lap and trim all around. One mobilization and one color.

Hardboard to vinyl or fiber cement

Same tear-off and wall prep, different siding. Vinyl costs less and needs no paint; fiber cement is heavier and slower to install.

Replace Masonite Hardboard Siding With LP SmartSide: questions, answered

Can Masonite hardboard siding be replaced with LP SmartSide?

Yes. The hardboard comes off, the sheathing is checked and repaired, the wall is wrapped and flashed, and LP SmartSide lap goes on in its place. SmartSide lap looks much like painted hardboard, so the house keeps its look. We set the new lap at a reveal close to the old one.

Why is my hardboard siding rotting at the bottom?

Hardboard is pressed wood fiber. Once the paint fails at the bottom edges and nail heads, it soaks up water, swells and rots. The bottom course near the ground, boards behind downspouts and boards under roof edges without kickouts go first.

Can I just replace a few rotted hardboard boards?

A few, yes, but hardboard is no longer made in most of the old profiles, so replacement boards are a close match at best. When rot shows on more than a few boards or on several walls, replacing a whole wall with new lap looks better and lasts longer than spot patches.

Can you replace hardboard siding on just one wall?

Yes. The worst wall is replaced first with new lap set at the same reveal, painted to match the rest. Many owners do the weather side now and the others later. When the paint is matched, it reads as one house from the street.

Should I replace hardboard siding with vinyl or LP SmartSide?

LP SmartSide looks closest to painted hardboard and takes paint, so the house keeps its look; it needs its clearances and sealed edges to last. Vinyl costs less and never needs paint but looks different up close. Fiber cement is the heaviest and slowest to install. We quote whichever you choose, with the same tear-off and wall prep.

Does new LP SmartSide need to be painted?

It comes either factory-finished in a set of colors or primed for paint. Primed siding needs a finish coat soon after it goes up. Painting is quoted as a separate line, or leave it primed and paint it yourself.

Recent JMB work, from our job log

59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and the builders we work with. Counts come straight from our job log; no customer names.

Related jobs we do

Page reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All siding pages

Where we work

Siding near you

Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: