Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
- This procedures includes guidance on silencing squeaky floors. Squeaks in floor boards may result from loose nails or boards or from a gap between the subfloor and the joists.
- When a subfloor is not tightly connected to the joists below or the floorboards above, a squeak results. This is usually caused by drying and shrinking in the subfloor members. The problem of a shrinking subfloor is similar to that of a shrinking or sagging joist; a space is created between the subfloor and the joist and a squeak occurs upon compression.
- A wood floor surface can be either a series of connected planks or parquet (small wood pieces arranged in decorative patterns). The wood used is either plain sawn or quarter sawn. Plank flooring, the more common type, is assembled by joining: butt joint, tongue and groove, shiplap, doweled or spline. Wood floors are usually secured to the under structure by countersinking nails, blind-nailing, or screwing and plugging.
- Flooring nails
- Wood dowel for plugs
- Hardwood wedge or shim, or length of 2x4 or 2x6 to bridge gap
- Drill to make pilot holes
- Screwdriver (power screwdriver works better with old, dry wood)
- Utility knife to cut excess from wedge
- Check for problems caused by decay: Signs of a decayed subfloor include buckling or discoloration of the finished floor, a spongy texture underfoot, water stains on the subfloor as seen from the underside, and general dampness.
- Probe the wood with an ice pick to determine the existence of rot.
- Inspect for signs of insect infestation such as mold fungus, bore holes, and sawdust piles.
3.02 ERECTION, INSTALLATION, APPLICATION
- First, try resetting the old nails.
- Cover the raised board with a carpet scrap or newspaper.
- Lay a wide wood block over the carpet and pound the block down with a heavy hammer.
- Tap all popped nails back into the floor with a nailset.
NOTE: If resetting does not stop the squeak, try the following:
- If the floorboard happens to be over a joist:
- Drive the flooring nail through the offending board at the squeaking point through to the joist.
- Drill a pilot hole measuring 3/4 the diameter of the nail.
- Drive the nail in at an angle to prevent it from pulling up as easily.
- Countersink the nail head and fill the hole with wood filler or color-matched putty.
- When only subfloor exists underneath, drive in two nails as above, but at opposing angles. The opposing angles prevents the boards from being pulled out if board shrinks or warps.
- If more holding power is required, use a screw.
- If the underside of the floor structure is accessible, screw loose board in place from below. If no access to the structure is available, screws can be adhered from above.
- Drill pilot holes to ease the installation; also use soap or paraffin to lubricate the screw.
- Counter-bore and plug the holes.
- If the squeak is caused by a shrunken or slightly warped board, drive a nail into the crack between the boards. Follow same nailing procedures as outlined in Section 3.02 B. above.
- For squeaks resulting from sub-floor shrinkage or sagging joists:
- Bridge gap between the subfloor and joist or sub- floor and finished floor by driving a small hardwood wedge or shim between the two. A shingle will not work because of its poor compressive strength.
- NOTE: THE GOAL IS TO TIGHTEN THE GAP NOT DRIVE THE WEDGE ENTIRELY IN.
- Nail a length of 2x4 or 2x6, several inches longer than the gap, to the joist tight against the underside of the subfloor.