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terra cotta restoration
The restoration of terra cotta can take many different forms. Below are different methods of terra cotta restoration.
Terra Cotta Replacement - True terra cotta replacement is recommended but not always available due to high costs and lengthy lead times. It also requires extra design and construction time because of the expansion of in-kind terra cotta when matching existing mold sizes. If time and budget permits, G.L. Capasso will secure in-kind terra cotta that is as close a match as possible to previously used materials.
Replacement with Substitute Materials - If a replacement material is deemed appropriate, G.L. Capasso will take great care to ensure that a material is chosen that does not impair the integrity of the building.
- Stone may be used to replace damaged terra cotta. Stone’s durability makes it highly regarded, but its increase in weight could be a concern.
- Fiberglass is used when elaborate ornamentation must to be duplicated. Drawbacks can include fire code compliance, color compatibility and poor aging.
- Glass Fiber Reinforced Concrete (GFRC) is very similar in nature to fiberglass. GFRC is lightweight and is able to be used on a large scale. Color compatibility and poor aging are drawbacks of GFRC.
- Precast concrete is ideal for the replication of detail. Precast concrete is cost-effective and can be produced in a timely manner.
Structural Stabilization - Structural terra cotta failures can develop due to fabrication defects, stresses from expansion and contraction, and water penetration. To successfully combat the effects of terra cotta deterioration, G.L. Capasso utilizes the following structural stabilization methods as appropriate (following thorough testing and analysis):
- Repointing: Repointing of terra cotta, which is severely deteriorated, is one of G.L. Capasso’s most useful terra cotta restoration techniques. Repointing is carried out with a mortar that has a compressive strength lower than the adjacent masonry unit.
- Glaze Spalling Repair: Glaze spalling is a common source of water-based terra cotta deterioration. It is important to seal affected areas to prevent further water entry. Recoating is not a permanent solution, but it does prevent the entry of more water.
- Minor Material Spalling Repair: Minor material spalling is treated in a manner similar to glaze spalling.
- Major Spalling Repair: Terra cotta that has spalled severely and lost most of its material and structural integrity needs to be replaced. Replacement methods are above.
- Repair of Structural Damage: Structural cracking, holes, or sign anchors should be permanently sealed. Holes and static cracks are able to be pointed or patched with appropriate proprietary patching material. Active cracks should be filled with elastomeric sealant.
Patching and Reglazing Terra Cotta – Repair systems for terra cotta have become a mainstream component in Historic Restoration work. This evolution is able to be attributed to the development of high quality, effective, specialty materials designed specifically for long-term compatibility with terra cotta substrates. With a record of more than 25 years of successful performance on many Terra Cotta Restoration projects, G.L. Capasso offers reliable and affordable services of patching and reglazing terra cotta units.
For more information on G.L. Capasso inc. services please call us at 203-469-2810 or email us at info@glcapasso.com.