Understanding Substrates in Older Homes – Lime Mortar Series Bonus Episode

<p>Before choosing your lime mortar or plaster, you need to understand your substrate.</p><p>In this bonus episode of Talking Conservation, Stephen and Rich explore the importance of knowing what's behind or beneath your mortar; from soft handmade bricks and old stone to chalk walls and cob. </p><p>Whether you're repointing, plastering, or rendering, understanding the substrate is critical to choosing the right mix and achieving long-lasting results.</p><p>We cover: </p><p>- What a “substrate” actually means in traditional buildings</p><p>- Common types found in historic homes (brick, stone, cob, timber) </p><p>- How substrate affects your lime choice and application</p><p>- Assessing problems and indicators of hidden issues </p><p>- Mistakes to avoid when applying lime to inappropriate surfaces </p><p>- Decision making, such as when to strip inappropriate materials </p><p>- Key questions to ask before starting any conservation work When to call in the professionals </p><p>- Keeping a record</p><p>▶️ Whether you're a homeowner or a professional working with heritage buildings, this video helps you avoid common issues and build with confidence.</p><p>👉 New to the Lime Series? Start here:</p><p>Ep.1: The Lime Cycle Explained – How lime is made and reabsorbs CO₂</p><p>Ep.2: Lime Mortar Types Explained – Key differences between air lime, NHL, pozzolans &amp; more</p><p>Ep.3 Part.1: Which Lime to Use? – Mortars for pointing &amp; bedding in older buildings</p><p>Ep.3 Part 2: Which Lime to Use? - Plasters and Renders</p><p>Ep.3 Part.3: High Exposure Areas &amp; Floors – Using lime in chimneys, ridges, parapets, and floors</p><p>🔔 Subscribe for upcoming episodes on more specialist areas </p><p>📞 For 1-to-1 advice or a consultation, visit: www.expertible.com</p><p>💼 Professionals: Training &amp; mentoring available at www.beconservation.com</p><p>#TalkingConservation #SubstratesExplained #LimeMortar #BuildingConservation #OldHouseDIY #HistoricHomes #TraditionalMaterials #LimePlaster #problemsolving #decisionmaking #professional help #heritageskills #limerender #lathandplaster #historictimberframes</p><p>Chapters00:00:00 – 00:00:50 </p><p>Introduction00:00:50 - 00:02:23 </p><p>What is a substrate?00:02:23 - 00:03:33 </p><p>Flint00:03:33 - 00:05:22 </p><p>Stone00:05:22 - 00:05:31 </p><p>Cob and earth00:05:31 - 00:06:12 </p><p>Wattle and Daub, lath and plaster00:06:12 - 00:06:56 </p><p>Multiple substrates00:06:56 - 00:08:24 </p><p>Behaviour of substrates (the science bit!)00:08:24 - 00:09:43 </p><p>Timber00:09:43 - 00:10:57 </p><p>Absorbency and moisture performance00:10:57 - 00:14:25 </p><p>Cement render on timber frame (case study)00:14:25 - 00:16:34 </p><p>Assessing problems and key indicators00:16:34 – 00:19:48 </p><p>Delamination and hammer testing00:19:48 – 00:23:02 </p><p>Decision making00:23:02 – 00:24:43 </p><p>Should I remove cement render/pointing?00:24:43 – 00:26:36 </p><p>Have I got layers of material?00:26:36 – 00:27:46 </p><p>A judgement call and bringing in professionals00:27:46 – 00:28:52 </p><p>Substrate preparation00:28:52 - 00:30:43 </p><p>Wetting down surfaces 00:30:43 – 00:32:05 </p><p>Plaster coats00:32:05 – 00:34:56 </p><p>Use of hair in mixes00:34:56 – 00:39:25 </p><p>Controlling the ‘set’00:39:25 – 00:40:14 </p><p>Lath and plaster00:40:14 – 00:41:33 </p><p>Dealing with modern interventions00:41:33 – 00:46:37 </p><p>Removing modern material00:46:37 – 00:49:30 </p><p>Surface finishes00:49:30 – 00:55:58 </p><p>Changing aesthetics and appearance00:55:58 – 00:56:56 </p><p>Key message – understand the building00:56:56 – 00:58:27 </p><p>The importance of keeping a record00:58:27 – 00:59:11 </p><p>Future episodes00:59:11 – 00:59:48 </p><p>Expertible00:59:48 – 01:00:05 </p><p>Close01:00:05 – 01:00:28 </p><p>Outro</p>