Historic sheet metal restoration
The federal treatments and Standards, the historic sheet metals and how to tell them apart, the mixed-metal and lead rules, a ten-step documented method with worked examples, and a published cornice case with the inspection routine that follows.
4 lessons · about 43 min · 14 diagrams · 2 videos
Version 1.0.0
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Lessons
0 of 4 complete
Lesson 1 · 11 min · 11 slides · 9 questions
Historic sheet metal restoration: principles and terminology
Why an old building is a record, the four federal treatments, how in-kind replacement and compatible substitutes differ, the historic sheet metals from tinplate to zinc, where a fabricator fits, and the lead and fire boundaries.
You will be able to: Define the four treatments, repair before replacement, in kind and substitute, name the historic sheet metals and tell them apart, state where AFS fits, and name the lead and fire boundaries of work on old metal.
Not startedStart →Lesson 2 · 12 min · 12 slides · 9 questions
Historic sheet metal restoration: materials, standards and design constraints
What the Guidelines and Preservation Briefs say about cleaning, painting, mixed metals and substitutes for terne; the Texas landmark review; historic sheet sizes against AFS pieces; copper weights; and the OSHA and EPA lead rules.
You will be able to: Apply the federal Guidelines, the substitute-material tests and the Texas review path to a sheet metal restoration, avoid mixed-metal and coating mistakes, relate historic sheet sizes and copper weights to AFS pieces, and apply the OSHA and EPA lead rules correctly.
Not startedStart →Lesson 3 · 10 min · 11 slides · 7 questions
Historic sheet metal restoration: methods and worked application
A ten-step documented method, recording and identifying old metal, finding the cause of damage, choosing the least intervention, detailing and approving new work, and two worked examples: pieces for a run and the lead-rule area test.
You will be able to: Apply a documented ten-step method to a historic sheet metal task: document and identify the metals, find the water, choose the least intervention, detail the new work, count pieces against AFS limits, and check the lead rules with sourced arithmetic.
Not startedStart →Lesson 4 · 10 min · 12 slides · 7 questions
Historic sheet metal restoration: defects, verification and case study
Defects in tinplate, terneplate, galvanized iron and zinc and their causes, the parts of a pressed-metal cornice, a National Park Service case study from findings through repair, attachment and paint, and the inspection routine and evidence packet.
You will be able to: Diagnose common defects in old tinplate, terneplate, galvanized and zinc work from symptom to cause, follow a published cornice repair from findings to paint, and set the inspection routine and evidence packet a reviewer needs.
Not startedStart →
Practical task
Build a restoration packet for one historic sheet metal feature of your choice (a cornice, a flashing, a painted roof edge): document it, identify its metals, find the cause of damage, choose and justify the least intervention, and set the inspection routine.
Hand in
- A decision rationale: the designation and review body, the treatment chosen and the Standard that supports it, each named
- A marked-up sketch or photo log of the feature showing each metal, each defect, and where water enters
- A metal identification table: for each part, the magnet result, finish, and any record that names the metal, labelled as observed or assumed
- A condition table: symptom, likely cause, evidence and the options, with options marked as the preservation architect's decision
- A hazard plan naming which lead rules apply (OSHA, and EPA if the building is covered) and which tasks are ruled out, plus a piece-count and joint-location sketch with every input labelled hypothetical or sourced
Rubric
| Criterion | Meets the standard when |
|---|---|
| Treatment | The chosen treatment is the least intervention that works, and the Standard or guidance behind it is cited by name and year. |
| Metal identification | Each metal is identified by at least two observations (for example a magnet test and finish), and an uncertain one is marked uncertain rather than assumed. |
| Cause | Each defect has a likely cause, with the evidence, and water paths are traced before any repair is chosen. |
| Mixed metals | No unlike metals or asphalt coatings are detailed against tinplate or terneplate, and each fastener matches the metal it holds. |
| Lead and fire | The plan states which OSHA and EPA rules apply and why, and no torch, abrasive blast or open flame is used on lead coatings. |
| Record | The packet names each source, keeps hypothetical inputs separate from measured ones, and sets an inspection routine with a log. |