If your house went up between 1968 and 1990, read this before you accept an exterior bid.
Hardboard siding, frequently called masonite after one of its manufacturers, is wood fiber compressed with resin and a binder into boards. Through the 1970s and 80s it was cheap, consistent and easy to install, which is why so much of Arvada, Westminster and Northglenn is wearing it.
Installed well and kept sealed, it performs adequately for decades. The problem is that it was frequently not installed well, and almost nobody keeps it sealed.
Hardboard is absorbent. The factory seals the faces, but every board gets cut on site, and those cut ends are raw fiber. If the installer did not prime them, which was common, water has a direct path into the board.
Once water is in, the fiber swells. Swelling breaks the bond between fiber and resin. The board goes soft, the surface delaminates, and the paint on top cracks in a pattern that follows the swelling rather than the wood grain.
Press the suspect area with your thumb. Sound hardboard is firm. Failing hardboard gives slightly and may feel spongy. If your thumb leaves a dent, that board is past saving.
This is the part that costs people money, so it is worth being blunt.
A swollen, delaminating board has lost its structural integrity. Paint is a coating a few thousandths of an inch thick. It cannot restore a board, it cannot stop the swelling, and because it is a moisture barrier on the outside face, it can trap water that is already inside.
What happens next is predictable. The house looks fine for a season, maybe two. Then the same boards crack and lift in the same places, and the homeowner concludes the painter used bad paint. The paint was probably fine. The substrate was already finished.
Repair makes an exterior project more expensive. There is no version of this where it does not. A bid that includes real hardboard repair will come in above one that does not, and the one that does not will look like better value right up until it fails.
What you should insist on is specificity. A bid that says "repair as needed" is not a commitment to anything. Ask how many sections, which elevations, and what the per-board cost is if more is found once work starts. We write it that way because vague language on this item is how surprises happen.
At some point the arithmetic flips. If a majority of the siding is failing, replacing the whole envelope with fiber cement or another modern product may make more sense than repairing dozens of sections. That is a conversation worth having with a siding contractor rather than a painter, and we will tell you plainly when we think you have crossed that line.
It looks like painted wood siding but has a very uniform, grainless surface or an embossed fake grain. The clearest tell is the failure pattern: swollen, soft bottom edges with paint cracking along the swell rather than along a grain.
Individual failed sections are cut out and replaced rather than repaired. Once the fiber has swollen and delaminated, there is nothing to restore. Sound boards nearby stay.
No. Paint cannot restore a board that has lost integrity, and by sealing the outer face it can trap moisture already inside. The repair has to come first.
It depends entirely on how many sections have failed, which is why we count them at the estimate and write the number down rather than saying repair as needed.
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Tell us what needs painting and send a few photos. Most Arvada projects can be priced without a site visit, and we will say plainly when yours needs one.
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