Gouged Nu-Wood fiberboard panel repair (C) InspectApedia BJFiberboard Ceiling/Wall Panel Repair & Paint
Repair procedures for fiberboard ceiling & wall panels

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Fiberboard insulating sheathing repair suggestions:

This article offers advice on procedures for reparing loose, warped, gouged or stained fiberboard ceiling and wall panels or tiles. We borrow from conservationists and we include some DIY homeowner procedure suggestions for non-historic buildings.

This article series describes and provides photographs that aid in identifying various insulating board sheathing materials used on building walls and roofs, such as Homasote, Celotex, Insulite, and Masonite, Upsonboard, Nu-Wood and other insulating board sheathing products.

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Repair or Painting Damaged Fiberboard Panels

Homasote type insulating sheathing board (C) Daniel FriedmanRepairs to Loose or Warped Fiberboard Sheets

Loose fiberboard can be re-attached using 4d finishing nails, though if your experience is like mine you'll need to drive longer nails, perhaps 6d on a 45 degree angle through the fiberboard into the stud or ceiling joist for the nail to hold the material in place.

Wilson and Snodgrass suggest that it may be possible to repair de-laminated soft fiberboard by injecting wheat paste between de-laminated layers, using a mixture of 1 tablespoon of wheat starch to 5 tablespoons of distilled water, microwaved 20-30 seconds until the mixture is stiff and translucent.

To make such a repair you may need to remove the panel or to form a press that can be applied to the damaged wall or ceiling surface.

Those authors describe removing a warped panel for repair so that it can be wet slightly, placed flat, and pressed while drying. I do not recommend this repair except for structures and panels of historic value, as in my experience, unless you're an experienced conservationist, trying to remove a 70 year old fiberboard panel from a wall or ceiling leads to ever worse damage to the panel.

Really? For other than historic preservation purposes, in my view it makes more sense to remove and replace damaged fiberboard panels with new ones of the same or similar texture and color. You won't find beveled Nu-Wood panels in new stock as the product has been out of production since about the 1970's or earlier.

If there is extensive damage throughout a non-historic structure, remove the panels entirely and replace them with drywall. That step brings your building closer to modern fire-code requirements, and it provides an opportunity to upgrade exposed wiring, plumbing, insulation and and to inspect the structure for hidden rot or insect damage.

You could instead leave the panels in place and cover them over with drywall: a step involving less mess. But you may find that the window and door trim and receptacles and switches in the room all need to be built-out, making this option expose its own achilles-heel.

Watch out: if you are working on a historic building you should not remove nor modify its materials before consulting with your local historic preservation authority.

Repairs to Dings & Gouges in Nu-Wood or other Fiberboard Wall or Ceiling Panels or Tiles

Gouged Nu-Wood fiberboard panel repair (C) InspectApedia BJ

BJ's photograph of Nu-Wood like fiberboard wall paneling above provides more information about the identification of these panels. - B.J. by private email 2017/07/29

The gouge contributed by the movers exposes the characteristic brown soft wood fibers that we'd expect in a fiberboard panel.

The vertical V-groove in this photograph is a bit narrower than the panel butt-joint v-groove photo that we provide below. So measuring between the actual butt joints will give the true panel width, probably 48".

Gouged Nu-Wood fiberboard panel repair (C) InspectApedia BJ

Repairs to a deep ding or gouge in fiberboard panels can take either

T111 siding texture copied to corner sealant using a drywall knife (C) Daniel Friedman

Above you can see my imperfect but satisfactory attempt to copy the rough texture of T111 plywood siding into what would otherwise have been smooth filler/sealant used at the corner of this building. I used a small 6-inch drywall knife, dragging it almost at right angles to the surface, holding the blade lightly. As the blade bobbled over the rough T-111 surface the parallel lines in the existing surface copied into the surface of the sealant to make that filler less obvious.

Once the panel surface has been repaired you'll need to re-paint the panel, wall, or ceiling if you don't want to look at an obvious, white patch job that doesn't match its surroundings.


Watch out: Because a few fiberboard products such as some Nu-wood (Conwed) ceiling tiles contained asbestos, see a discussion of possible asbestos at plants producing these cellulose-based ceiling tiles produced at ASBESTOS CEILING TILE FAQs

Watch out: about fire safety.

I like these old fiberboard walls, but I am compelled to add the caution that for improved fire-resistance to meet modern codes you may ultimately decide to laminate a layer of drywall over them - something to discuss with your local building inspector. While treatments were done to some products to improve fire resistance their fire rating, particularly after many decades of service and possible deterioration, might be in question.

How to Paint Fiberboard Panels

Fiberboard ceiling panel, US FPL excerpted from

Re-painting existing, already-painted fiberboard panel or tile ceilings or walls requires using an interior paint that is compatible with the paint that's already on the surface.

If the existing fiberboard surface is stained from previous leaks, and assuming you were smart enough to fix the leaks before trying to paint, you may need to seal the stained area with a lacquer primer-sealer to prevent the stain from bleeding-through the new paint job.

This is particularly necessary on fiberboard panel paint jobs since solvents in some paints (as well as some water leaks) can dissolve tannins and other components in the panel to form a brown or black stain that may simply bleed through a new coating of a water-based latex or acrylic paint.

Watch out: using an incompatible paint on an already-painted surface can cause the new or old or both layers of paint to fail by peeling, bubbling, or falling right off of the surface. Details are at INCOMPATIBLE PAINTS [separate web article at InspectApedia].

Painting previously-un-painted fiberboard panels, comes up when a fiberboard-covered interior room is being converted from storage to living space or "modernized" or when you're sick of looking at stained Beaverboard.

If you must paint previously un-coated fiberboard, the job may not be as easy as you think: a bleed-through problem may infect your paint job unless you first coat the fiberboard with a lacquer primer/sealer, just as I discussed above.

Above: a painted-over Nu-Wood ceiling discussed below in a Q&A about NUWOOD ASBESTOS CONTENT

Watch out: as we warn throughout these articles, don't start slapping paint onto un-painted surfaces of a historic building before you've consulted your conservation authority.

Note: presently in the U.S. a separate company, Nu-Wood Synthetical Architectural Millwork, Syracuse, NY, produces polyurethane-based faux stone and brick panels and columns used indoors and outdoors. These products are not those described in the article above.

Watch out: if you're worried about asbestos in fiberboard panels or sheathing products, wee SHEATHING, FIBERBOARD ASBESTOS CONTENT

Fiberboard Conservation, Repair, Painting Research

Nu-Wood Interiors catalog pages (C) InspectApedia


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