On this wall, there is a fibrous, black sheeting material made by Gold Bond Building Products. The board is nailed to the 2x4 framing along the length of the wall. The are some areas where the board has been cut away to make access for plumbing, wiring, etc.
Fiberboard products have been widely used on building exteriors as a non-structural wall sheathing, even on some roofs as roof sheathing, and on building interiors as a ceiling or wall covering.
When used with sound-deadening board and gypsum wallboard, outside walls become excellent sound barriers against outdoor noise. Fiberboard sheathing is water repellent, forms a weather-tight cover for walls, and eliminates the need for building paper with most sidings.
Unless the fiberboard actually absorbed water, can't be dried, and / or is damaged, replacing it is not likely to be cost effective nor necessary. Unless there is a serious mold problem I'd leave the sheathing in place.
While it should never be used outdoors or in an application where it's regularly exposed to water, there are two approaches to “waterproofing” MDF so it can withstand moisture in high humidity areas: use ure Resistant (MR) MDF or make it water-resistant yourself.May 25, 2018
Asbestos in Low Density Board (LDB) "Fiberboard" Products. Some low density fiberboard products like those described here were widely manufactured and distributed including in the U.K. and Australia; these products are particulary hazardous if disturbed as they are soft and they contain high levels of asbestos.Dec 15, 2012
Hard fiberboard can be used as wall slab, door board, floor, furniture and other decorations instead of wood. And the soft fiberboard whose apparent density is low(< 400 kg/m3) and porosity is high, often used as heatproof or acoustical materials.
For all structural purposes, plywood is much stronger than fiberboard, reveals Bob Vila. Plywood is made from several individual layers glued together perpendicular to each other to provide strength. Fiberboard is made from individual random chunks of wood glued together under pressure without grain patterns.
You can update or otherwise improve fiberboard by painting it. To do this correctly, however, you will need to take a little extra time priming it than you would solid wood furniture because fiberboard is more porous. Other than that, painting fiberboard is similar to painting wood.
Fiberboard cement siding can be hand-nailed, but because it's so much harder and more brittle than wood, you have to predrill holes near any edge.Jul 14, 2021
Re: Vinyl siding over Celotex Absolutely not, vinyl siding will not have any strength to offer the structure on its own. If you really can not afford to do it properly then I would remove any rotted old siding and replace it with plywood and then install house wrap and vinyl siding over that.Feb 2, 2013
Fiberboard was not "designed to get wet" as CRS offered in his opinion. Fiberboard or insulating board was traditionally treated with a water resistant surface coating such as wax or asphalt; that product was designed to shed water or to resist moisture.