Boyenga Team · Burlingame Eichlers What's mine worth?

Burlingame Eichlers  /  The folded-plate roof

Roof forms

The most interesting roof in Burlingame rests on one sentence.

Of all the Eichler roof types — flat, low gable, A-frame, shed — the folded plate is the rarest, and Burlingame is the place it is reported. We take that seriously enough to have gone looking for a second source, and we did not find one.

Consider, for example, the design found in Burlingame with a lively, folded plate roofline over the entry.

Dave Weinstein, Eichler Network, writing on late Eichler models. No plan number. No year. No address. This is the whole of it.
A charcoal Eichler in Burlingame, with rust-red fascia and a roof that rises to a peak, falls, and rises to a second peak above an open entry court you can see straight through.
The roof that folds twice. Up to a peak, down, up to a second peak, down again. Seen square-on from the street this is as close to a folded plate as a house gets, and it is the form Eichler Network's one published reference to a Burlingame folded-plate roofline most plausibly describes. The entry is a pass-through — roofed, open at both ends, with the front door set back inside it.
How a folded-plate roof carries itself, drawn as a section A diagram comparing a flat roof deck, which needs deep beams to span, with a folded plate, where the roof is bent into a zigzag so the fold itself gives the structure its depth and it can span further with less timber. A FLAT DECK SPANS ON THE DEPTH OF ITS BEAMS BEAM DEPTH DOES THE WORK SPAN A FOLD SPANS ON ITS OWN GEOMETRY THE FOLD IS THE DEPTH SAME SPAN, SHALLOWER TIMBER WHAT IS DOCUMENTED IN BURLINGAME A FOLDED-PLATE ROOFLINE OVER THE ENTRY — ONE SENTENCE, DAVE WEINSTEIN, EICHLER NETWORK. NO PLAN NUMBER. NO YEAR. NO SECOND SOURCE. EVERYTHING ELSE ON THIS PAGE IS GENERAL.
DIAGRAMMATIC. THE PRINCIPLE IS GENERAL STRUCTURAL ENGINEERING, NOT AN EICHLER DETAIL DRAWING. WE HAVE FOUND NO SOURCE DESCRIBING EICHLER'S OWN FOLDED-PLATE CONSTRUCTION — DECK THICKNESS, FRAMING OR SEAMS — AND HAVE NOT DRAWN ONE.

How thin the record is

Three official surveys list Eichler roof types. None includes this one.

DocumentRoof types it enumeratesFolded plate?
City of San José, Eichler design standards Front gable (typically 2:12), flat, flat-with-shed, flat with a steep gable over the entry — four street-visible types No, explicitly not listed
Balboa Highlands HPOZ preservation plan, Los Angeles Flat, A-frame, slantNo
Fairglen Additions, National Register nomination Flat and 2:12 gable, plus an A-frame inserted into a flat roof (model SJ-4D) No

Two readings are available, and we are not going to pretend to know which is right.

One: the folded plate was genuinely a one-off or near one-off, used on a single Burlingame model, which is exactly why no tract-wide survey elsewhere records it. That would make it the rarest Eichler roof in existence and a real find.

Two: the single sentence is loose usage — a steep folded-looking entry canopy described impressionistically rather than technically — and there is no true folded plate here at all.

What would settle it is a photograph, or a plan sheet, or an address. We have none of the three. What we do not have, and will not print, is the “BC-384” plan number that one site attaches to a “three-folded-plate entry” — neither that designation nor that phrase returns anything anywhere. Why we drop it →

If you live on one of the eight streets and your entry roof zigzags, you may own the only documented folded-plate Eichler. Send us a photograph and we will put it on this page with your name on it.

If you have one

What a folded plate means for maintenance.

A folded plate is all valleys and ridges. Every fold that turns downward is a gutter you did not ask for, and every one that turns up is an exposed arris. Compared with a flat Eichler roof, there is far more linear footage of edge and joint per square foot of roof.

That has consequences at re-roof: more flashing, more labour, and a roofer who understands that the geometry is structural. A contractor who proposes to flatten the folds to simplify the job is proposing to remove the thing that makes the roof span.

It also matters for insulation. Late Eichlers came with fibreglass in roof and walls, but the original flat-roof assemblies were famously thin, and a folded roof has a larger surface area than the plan area beneath it — more envelope per square foot of house.

A limit on what we can tell you. We found no source describing Eichler's own folded-plate construction — deck thickness, framing, seam detail. The structural principle on this page is general engineering, not an Eichler detail drawing, and we have not drawn one we cannot source.

Talk to us

Does your entry roof zigzag?

We are trying to find the Burlingame house behind that one sentence. A photograph from the kerb would do it, and we will credit you.