Bonding coat
The bonding coat, bond coat or base coat in construction terms usually refers to the first coat of gypsum plaster which is laid on the existing surface such as stone, brick or existing plaster. The term base coat is usually used to mean the same but for lime based plaster products or clay based plaster products. Base or bond coat can also be used to describe the first layer of external render applied directly to the existing external structure of a building such as stone or brick, though this is most often referred to as a parge coat.
The bond or base coat is usually a coarse plaster or render which can be applied in thicknesses between 10-20mm, it has greater adherence qualities and is used to even out the existing surfaces of the wall, internally in the case of plaster and externally in the case of render. Once hardened one or two more layers can be applied, finished by the final coat, finish layer, sometimes called skim coat which is normally a thinner layer applied at 2-5mm thickness.
See also: plaster, lime plaster and clay plaster
[edit] Related articles on Designing Buildings
- Boss plaster.
- Caulk.
- Cement.
- Cement mortar.
- Clay plaster.
- Daub.
- Decorative metal ceilings.
- Dry lining.
- Drywall.
- Finishes.
- Fresco.
- Grout.
- Gypsum.
- Inspecting historic fibrous plaster ceilings.
- Lath and plaster.
- Lime plaster.
- Making Magnificence: architects, stuccatori and the eighteenth-century interior.
- Mortar.
- Parge coat.
- Plaster.
- Rendering.
- Stucco.
- Tanking.
- Tiles.
Featured articles and news
Costs and insolvencies mount for SMEs, despite growth
Construction sector under insolvency and wage bill pressure in part linked to National Insurance, says report.
The place for vitrified clay pipes in modern infrastructure
Why vitrified clay pipes are reclaiming their role in built projects.
Research by construction PR consultancy LMC published.
Roles and responsibilities of domestic clients
ACA Safety in Construction guide for domestic clients.
Fire door compliance in UK commercial buildings
Architect and manufacturer gives their low down.
Plumbing and heating for sustainability in new properties
Technical Engineer runs through changes in regulations, innovations in materials, and product systems.
Awareness of the Carbon Border Adjustment Mechanism
What CBAM is and what to do about it.
The new towns and strategic environmental assessments
12 locations of the New Towns Taskforce reduced to 7 within the new towns draft programme and open consultation.
Buildings that changed the future of architecture. Book review.
The Sustainability Pathfinder© Handbook
Built environment agency launches free Pathfinder© tool to help businesses progress sustainability strategies.
Government outcome to the late payment consultation, ECA reacts.
IHBC 2025 Gus Astley Student Award winners
Work on the role of hewing in UK historic conservation a win for Jack Parker of Oxford Brookes University.
Future Homes Building Standards and plug-in solar
Parts F and L amendments, the availability of solar panels and industry responses.
How later living housing can help solve the housing crisis
Unlocking homes, unlocking lives.
Preparing safety case reports for HRBs under the BSA
A new practical guide to preparing structural inputs for safety cases and safety case reports published by IStructE.
Male construction workers and prostate cancer
CIOB and Prostate Cancer UK encourage awareness of prostate cancer risks, and what to do about it.