Resources for Historic Homeowners

John Leeke's Historic HomeWorks™ Question & Answer Column

#36 Piano Load

On a home built in 1750,would it be possible for the weight of an upright piano to cause damage to the beams in the basement? All floors and beams are original. Is there any way these beams could be repaired by not jacking up this three story home as not to cause more damage to the structure in the process? What would you say the cost could run?

The weight of a piano could cause problems, but many of these old places were built to take such a load. To know for sure in your case, you should have a contractor or engineer examine the structural framing of the floor to determine its condition and if it can take the intended load.

Structural repairs can sometimes be isolated to a limited area, and other times can indeed "telegraph" throughout a structure, disturbing the finish woodwork and plaster as the underlying framework is shifted slightly.

To determine the costs, first you, along with the contractor or engineer, must determine the type and materials of the framing, then its condition and what needs to be done. Once you know that you can determine the costs.

Lockset Cleaning

I have an old front door mortise lockset that is complete, but doesn't work very well. The bolt doesn't really spring very well. What are the steps for cleaning and restoring this thing? I opened it up, and its full of nasty grease. How do I go about cleaning all of that out? I assume I'd soak it in something, but I don't know what. Anything else I should do while I'm in there? Thanks.

Some locksets are quite simple devices and others are complex mechanisms. If your lockset seems too complex for you deal with, the best thing might be to take it to a locksmith for cleaning and adjustment.

If you decide to do it yourself, the first thing to do is take pictures and notes so you can remember how all the parts go together. If it's not too complex a mechanism you might disassemble it, but be careful, sometimes there is spring pressure that sends parts flying around the room.

The old-time standard is to clean the parts one-by-one with a steel wire brush and kerosene--but kerosene very flammable so be careful not to burn the place down!

A safer way would be to soak them in a TSP & water solution for a few days, then scrape and scrub off all the oil & grease. Wear heavy rubber gloves & splash-guard goggles. Be careful to not scratch soft brass parts by using a hardwood stick (like a popsicle stick, or tongue depressor) whittled down to get into the nooks and crannies.

After the parts are clean, reassemble to see how they operate and if any parts are broken, worn or have lost their spring. Probably it was just the gunk gumming up the works, and you can lubricate rubbing surfaces with a drop of light oil (3-in-1 Oil) here and there, or the tiniest dab of Vaseline in just the right place.

Plaster Repairs

I have an 1890's building with plaster walls probably from the 1920's or before. The plaster was installed for wallpaper since it has a rather rough texture. In one room, a skim coat of finish plaster had been put over the top of this original plaster (date unknown) and has developed several cracks both along cracks in the original plaster as well as surface cracks in the finish coat. The skim coat comes off the original plaster easily with a putty knife. I am in the process of removing the surface coat back to the original plaster, but would like to paint the room again. Since the original plaster is too rough to paint, I will be skim coating the plaster again. As the previous skim coat did not form a good bond with the underlying plaster, I feel the original plaster was probably coated with a wallpaper sizing when it was originally installed. Is there anything I can do aside from scrubbing the original plaster with a strong solution of TSP to get the new skim coat to adhere to the original plaster and will the skim coat stick this time? Thanks. -- Calvin Wells

I suspect you are right in assuming this rough and relatively soft plaster was intended for papering. The skim coat may have failed for many reasons, but the most likely is differential expansion. The underlying plaster and wood lath system moved with changes in moisture and possibly structural shifting. The stiffer skim coat cracked because it was stronger and then lost its bond at the relatively weak surface of the old plaster.

I suggest you back up a little and reconsider your plan to skim coat. The original builders knew this plaster would move and that is why they papered. What ever you do, it should allow for the continuing movement. If you really don't want to repaper you could applying a fabric backing to the surface and then paint the fabric with latex paint which is more flexible than most oil-based paints.

If you must skim coat, stabilize the old plaster surface by coating with bonding agent. Bonding agent will soak into the porous surface sealing it and acting like an adhesive for the skim coat. It is available at masonry suppliers. I can't recommend a specific skim coat material without seeing the wall, but whatever you put on should not be stronger than the plaster beneath or you will run into problems later on. Test different kinds of joint compound, fillers and skim coat plasters by applying them to cardboard sealed with bonding agent. Determine which is weakest and most flexible by bending the cardboard, breaking the coating.

If this is too much trouble, The Glidden Company makes a plaster impregnated fabric product that you hang on the wall, dampen and trowel into place. This bridges over a certain amount of gaps and cracks in the old plaster surface.

Always test your selected materials and methods of application on a small section of the wall in an out of the way place to be sure they work and give you the results you want.


Structural Assessments & Repairs

George Yonnone Restorations
Box 278. West Stockbridge MA 01266
(413) 232-7060

Plaster Repairs & Materials

Here are two products of this type:

By Specification Chemicals, Inc.
824 Keeler Street
Boone, Iowa 50036
Toll Free (800) 247-3932
Phone (515) 432-8256
Fax (515) 432-8366

By Glidden Paints, available at ICI Dulux Paint Centers around the country.


John Leeke is a preservation consultant who helps homeowners, contractors and architects understand and maintain their historic buildings. You can contact him at 26 Higgins St., Portland, Maine, 04103; or by E-mail:; or log onto his website at:

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