Antique water tank in an attic? Justin Morril Smith (C) Daniel FriedmanOld House Mysteries & Their Solutions

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Old house detective work:

Questions & answers identify old, odd, unusual components, conditions, problems, in, on or around older buildings. This article posts photographs of unidentified objects, components, systems found in older buildings. We include descriptions of the items or conditions observed and we speculate on the original source or purpose of the "thing" being studied.

We include research and research suggestions that help explain old building questions, observations, components, or materials whose original use, source, or purpose may be otherwise lost in the fog or murk of time. Page top photo: antique box found in the attic of the Justin Morrill Smith house seems to receive water and send it somewhere; it's too small to be a cistern.

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Old House Mysteries, Detectives, & Explanations

Roof sheathing using perforated boards sporting ceramic bushings (C) David Grudzinski The attic water tank shown at the top of this page is described at ROOFTOP WATER TANKS under Attic Water Storage Tanks or Cisterns.

Below we start on a new old house mystery.

Perforated Board Roof Sheathing with Ceramic Insulating bushings - where did these boards come from?

Home owners, home inspectors and other building professionals enjoy figuring out the answer to "What the heck is that?" or similar exclamations that describe unidentified objects, systems, components or conditions in buildings. Old building mysteries may involve a weird electrical control, a tank that has no apparent use, or things that just don't seem to belong. From objects to odors, sights to sounds, we publish those findings here along with the solutions to these puzzles.

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Shown here, roof sheathing boards on a 1955 wood frame home. The boards are perforated at regular intervals and most of the perforations include a concave white ceramic bushing stamped 395/2.

2016/06/15: Professional home inspector and frequent contributor to InspectApedia David Grudzinski writes:

I have a strange find from a 1955 home today. The wood sheathing in the home and roof deck has hundreds of small Ceramic plugs installed, and I have no idea what that is, or what it may have been for. Attached are a few photos.

I took one of the plugs out and its concaved on one side, and has stamped numbers on the bottom. The stamped numbers are 395 over 2.

Roof sheathing using perforated boards sporting ceramic bushings (C) David Grudzinski Roof sheathing using perforated boards sporting ceramic bushings (C) David Grudzinski

Initial Speculation from DF:

Here's a working half-baked guess based on my discovery of a house built out of packing crates and some other recycled-material homes: I suspect that someone recycled maybe even stole these boards to use as roof sheathing from some prior application. That is I guess the holes and plugs had nothing functional to do with the house where you saw them.

Now the challenge is to find out what the heck those perforated boards were used for.

We have some clues:

Did you happen to note the dimensions, width, length of these boards? Do you know the plug and hole dimensions; sometimes those details help me come up with the original application.
Where is the home located? What industries were nearby in the 1950's? Do we know the occupation of the original owner (unlikely I realize) and do you think it was an owner-built house?

David Replies:

The home is 1955, in Cumberland RI, I do not know who built it, but its a standard style home we see lots of here in NE, a split level ranch.

The board width is near 14 inches and the length are 10 ft or better.

The plugs are 1/2 inch exactly. The boards do not all have them so I agree they were a salvage. I initially suspected some past association with radiant electric heat, but I would expect them to be uniformly around the house, and not on roof sheathing.

In This area there were textile mills, but I can't connect any textile to this application.

... I also find it odd that the ceramic plugs are numbered as that would seem counter productive for such an insignificant part unless it was a critical part. And one side being dimpled is strange unless it was to reflect heat back?

Below, David gives us a closer-look at the ceramic insulator, grommet or more likely "bushing".

Roof sheathing using perforated boards sporting ceramic bushings (C) David Grudzinski

DF replies

These boards came from some large industrial or research project, probably used indoors as the peeling finish looks like something that wasn't for outside. It seems to me these roof sheathing boards were "re-purposed" from some earlier application. Re-use of building materials in construction has a very long history.

And thinking like you I guess the source was local or local to the employment of whomever salvaged or re-purposed the boards. Covered by roofing there is no apparent reason that these insulated perforated boards would have sported those features specifically for use as roof sheathing, though I wouldn't rule out testing perforated boards as a substitute for spaced wood furring strips as a roof sheathing system onto which slates and other roofing plenty of needing ventilation. - Seems rather unlikely, though.

[Do we know the original roof material on this home?]

Ceramic suggests maybe electrical (or as you suggest a concern for static electricity) but size and number of boards makes it odder, perhaps salvaged from a large or one-off industrial project;

If some of the boards were flipped over it would be instructive to compare the other side, looking for a difference in finish or any material deposits. Wear marks or stampings on boards might also give a clue. The numbered ceramic part may have been made for wider application than just in the boards were we're seeing it.

Wood was a natural insulating material; The Blackstone Valley Electric Company in RI built one of the largest early transformers ever seen.

The material could also have been part of some study or machine built as a New Deal project.

I researched patents, ceramic bushings in wooden boards at intervals, &c. and came up with a few projects but nothing that looked right.

A look at photographs of early textile mills shows hundreds of rows of spools of texctile thread, usually placed vertically, at regular intervals. If these boards originated in a textile mill perhaps the bushings held spool spindles.

Examples of diagonally-placed peforations in boards used in textile mill applications: Spool Racks & Bobbin Boards, Bobbin Holders, Creels, Spindle Shanks using a porcelain eye, grommet or bushing

Spool rack, Black patent 1921 at

Black patent diagonally perforated board example -

Thoma patent for textile machine construction 1944 - at

Home Inspection Educator Alan Carson Adds Questions

Clearly re-used from something big and probably industrial – I agree.

- Alan Carson is a principal with Carson Dunlop Associates, a Toronto home inspection & home inspection education & report writing firm.

Other Old House Resources & Research

The Second Story: tips for identifying mysterious objects in buildings

Previously on "Old House Mysteries" These Have Been Solved

Solar Water Heater in Attic

Old house solar heater in attic (C)

Above: a partial view of a mysterious attic tank construction. This device is described and was finally explained at SOLAR WATER HEATER ANTIQUE - describing the purpose of a weird wood wrapped, gypsum-insulated tank in a 100-year-old Riverside California home attic.

Attic Expansion Tank for Hydronic Heating System Boiler

Steel tank in a Poughkeepsie Attic, Stamped with ? Plumbing Co., Poughkeepsie NY Queen City Tanks (C) Daniel Friedman

Above: a round galvanized cylinder hanging from rafters in an attic, next to an abandoned chimney and stamped with the name of a plumbing company, Poughkeepsie, New York, and Queen City Tanks. Nearby steel strapping held something else that has been removed. This tank is identified and explained at ATTIC EXPANSION TANKS, HEATING.

First Generation Electrical Power Distribution in New York City

DC cable unearthed from a New York City street (C) Daniel Friedman Conrad Milster

Above we're looking at the cut-end of what is most likely a section of original DC or continuous current distribution cabling salvaged from a NYC trench. At at STEAM BOILERS GENERATORS CONTROLS, PRATT we explain that the Pratt steam room engineer and himself a collector and historian, Conrad Milster spotted these "pipes" while looking into a utility trench where Con Ed was doing some other work.


Continue reading at HISTORIC & OLD BUILDINGS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see ANTIQUE CHEST Ricketts - Strause HISTORY - research tracks down the long history of an old wooden chest

Or see HOPPUS MEASURER - before carpenters were good at arithmetic

Or see NOISE / SOUND DIAGNOSIS & CURE - home, includes a discussion of ghost noises in or at buildings


Or see OLD ELECTRICAL WIRING TYPES - photo guide to older types of electrical wiring found in buildings


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