Hygroscopic Bathroom – January test
Green – Humidity
Yellow – Temperature
Interstitial – behind 50mm of Hemp and Lime, in front of 225mm clay brick, at the top of a room, above a bath and shower.
Temperature and humidity monitoring by Pier Sadler Consulting. Data files available on request, drop me a line.
Conclusion. No interstitial condensation, no moisture build up, no correlation with internal humidity. If interstitial humidity reading is amplified it can be seen to follow external temperature. Relates more to outside than in. Outperforms u-value due to thermal inertia and hygroscopicity, no latent heat lose effect from condensation or evaporation and recovering heat from the peaks of warm moist air.
Hydrothermal passive heat recovery?
Casting Hemp and Lime connects and engages with the wall even when challengingly thin layers are applied.
Methodology
Preparation
The resurrection of a unique surface preparation method and traditional wall fixing. The timber ‘Dochan’ quickly flattens out any uneven surface for a true, flat, vertical finish that holds together rather than disturbing old lime mortar and loose stone or brickwork.
Mixing
Revolutionary small scale hempcrete mixing process for safe clean material handling making domestic projects accessible and affordable. Measured and consistent mixing with the correct amount of water will prevent drying problem and improve performance.
Casting
The shuttering is secured to the Dochans and the Hemp and Lime cascades in. No stratified layers with a flat tamping tool, use a sharp stick to ‘poke it’ and knit it together. Quicker, easier, cheaper and more effective than building out with a lime plaster base coat
Results
No moisture build up, no correlation with internal humidity. Interstitial humidity follows external temperature. Relating to outside not in. Outperforms u-value due to thermal inertia and hygroscopicity, no latent heat effect from condensation or evaporation. Hydrothermal passive heat recover from buffering the peaks of warm moist air?
Case Studies
Hemp Lime projects
The damp Victorian terrace, steamy hygroscopic bathroom and open plan emancipated kitchen, every home has cold spots.
Talks and workshops
Hemp Lime training
Renovation, conservation and new build construction. Preparation, mixing and casting onto existing masonry, infilling traditional timber frames and solid wall monolith construction.
Advice and consultancy
Hemp Lime preparation
Damp pathology, building principles, design critique, project planning and team building.
Bristol Hemp and Lime
Hygrothermal passive heat recovery, solves damp problems with the secondary effect of improving the thermal efficiency of older buildings.