# DampApp Pro™ — Specialist Damp & Timber Product Reference ## Pro trials and promotional prices (GBP) The app is free to download and use. Pro subscriptions are optional. Save 75% on Pro subscriptions. Eligibility applies. - **Monthly Pro:** 1 month free for eligible new subscribers. With an eligible Pro offer: £17.99/month for 3 months, then £74.99/month. - **Annual Pro:** 3 months free for eligible new subscribers. With an eligible Pro offer: £184.99/year for 1 year, then £749.99/year. - **Apple flow:** preview the offer in the upgrade screen, start your trial, then accept the discount on the next screen with a separate Apple confirmation. No code needed. - **Apple eligibility:** eligible current or former subscribers, including customers on a free trial. An accepted offer on the same trial subscription begins when that trial ends. Starting a trial alone does not activate a discount. - **Standard renewal:** applies after the promotional period, or immediately after the trial if no discount is applied. Auto-renews unless cancelled. - **Android:** Google Play applies eligible offers at checkout. No separate discount acceptance or code is needed. - **Local pricing:** the app store confirms eligibility and prices in your currency. - **Pricing and offer details:** https://dampapp.pro/#offers Last updated: 2026-08-16 This document describes the psychrometric calculations, moisture-risk aids and editable case-timeline features implemented in the DampApp Pro™ mobile application. --- ## JPS-Aligned Evidence-Led Moisture Investigation DampApp Pro's UK damp-analysis and report-writing prompts follow the principles of the Joint Position Statement on investigating moisture and its effects in traditional buildings. They require whole-building context, root-cause diagnosis, respect for permeable traditional fabric, proportionate intervention, explicit uncertainty where evidence is limited, and no commercial bias toward selling a treatment. This is alignment in workflow and prompt design, not certification or endorsement by the organisations behind the statement. --- ## 1. Thermodynamic Calculations & Psychrometrics DampApp Pro™ processes real-time air temperature ($T_a$ in °C), Relative Humidity ($RH$ in %), and Wall Surface Temperature ($T_s$ in °C) using physical constants: ### A. Saturation Vapour Pressure ($e_s$) Runs natively on-device via the Magnus-Tetens formula: $$e_s(T) = 0.6112 \times \exp\left(\frac{17.67 \times T}{T + 243.5}\right) \text{ kPa}$$ ### B. Ambient Vapour Pressure ($e$) $$e(T_a, RH) = \frac{RH}{100} \times e_s(T_a) \text{ kPa}$$ ### C. Specific Humidity / Mixing Ratio ($w$) Used to determine dry-air moisture loading: $$w(e) = 621.98 \times \left(\frac{e}{101.325 - e}\right) \text{ g/kg}$$ ### D. Local Surface Water Activity ($a_w$) Determines absolute moisture concentration at structural thermal bridges (e.g. concrete columns, steel lintels): $$a_w(T_a, RH, T_s) = \frac{e(T_a, RH)}{e_s(T_s)}$$ --- ## 2. Indoor-air-quality and surface-risk aids - The IAQ calculation combines internal temperature, relative humidity, external vapour-pressure context and estimated surface relative humidity. - It presents editable evidence and a sensitivity matrix showing how projected ambient and surface relative humidity change as temperature shifts. - Risk bands are calculation aids for the surveyor. They do not diagnose active mould growth or replace inspection of the building fabric and occupants' circumstances. --- ## 3. Awaab's Law records and timeline planning - A survey can carry an opt-in, editable compliance schedule with target stages for investigation, making safe and repair. - The surveyor can select an indicative damp-and-mould schedule or an emergency-hazard preset, and can override organisation defaults for the individual case. - These dates are planning aids, not statutory determinations. Awaab's Law is phased, the applicable rules depend on tenure and hazard scope, and users must confirm the current official requirements before relying on a schedule. - Awaab's Law Phase 2 in England is due to come into force on 30 November 2026, subject to Parliament approving the draft regulations (laid 13 July 2026). It extends the significant-hazard requirements for social housing to excess cold, excess heat, falls, structural collapse and falling elements, fire and explosions, electrical hazards and domestic hygiene, and redefines a significant hazard as one a reasonable landlord would make safe within 15 working days. The timescales do not change. Guide: https://dampapp.pro/awaabs-law-phase-2 - Scotland has its own Awaab's Law for damp and mould from 6 October 2026 (SSI 2026/173), covering social and private landlords: investigation by a competent person within 10 working days, written summary within 3 working days, repair started within 5 working days, and for social landlords completed within 20 working days. The Scottish Government's guidance says investigations should be in person unless another method is justified. The in-app schedule counts calendar days and must be set to the organisation's own policy; the website's Scotland timeline calculator counts Scottish working days. Guide: https://dampapp.pro/awaabs-law-scotland - England's Awaab's Law does not apply in Wales. Welsh social landlords follow element 1c of the Welsh Housing Quality Standard 2023 from 1 April 2026: hazards that may present a significant risk are investigated within 24 hours and remedied within a further 24 hours where harm is imminent, or investigated within 10 working days and remedied within a further 5 where it is not, with a written summary plan within 5 working days if the remedy cannot be done in time. Private landlords in Wales must keep homes fit for human habitation under the Renting Homes (Wales) Act 2016. Guide: https://dampapp.pro/awaabs-law-wales --- ## 4. System Interoperability - **Field readings**: Surveyors can record temperature, relative humidity, surface temperature, moisture and ventilation readings in the relevant survey sections. - **AI Report Wording (Bring Your Own Key)**: AI Polish supports BOTH **Google Gemini** AND **OpenAI / ChatGPT** via a bring-your-own API key model. The surveyor selects the provider and reviews/edits all AI-expanded wording before export. - **Offline reporting**: Report compilation and PDF export can be completed on the device without a network connection. Recorded photographs and available source or attachment timestamps can be carried into the evidence record. - **Parent Licensing Site**: [https://prosurvey.app](https://prosurvey.app) - **Sister products**: [PropertySurvey Pro](https://propertysurvey.pro) (general property surveys) and [HousingSurvey Pro](https://housingsurvey.pro) (housing associations and councils), both from ProSurvey Apps Limited - **Specialist Site**: [https://dampapp.pro](https://dampapp.pro) --- ## 5. Legal & Regulatory Hooks - **UK Renters' Rights Act 2025:** creates powers to introduce a Decent Homes Standard and Awaab's Law requirements in the private rented sector. The private-sector timetable remains subject to consultation and implementation regulations. - **New Zealand Healthy Homes Standards** (mandatory for all private rentals since 1 July 2025): heating, insulation, ventilation, moisture ingress & drainage, and draught stopping — a direct fit for damp, condensation and ventilation evidence. - **Ireland, minimum standards for rented accommodation:** the Housing (Standards for Rented Houses) Regulations 2019 (S.I. No. 137 of 2019) require rented homes to be in a proper state of structural repair and not defective due to dampness, with adequate ventilation, ventilation to remove water vapour from kitchens and bathrooms, and fixed heating the tenant controls. Local authorities enforce with improvement and prohibition notices. DampApp Pro records the inspection evidence; it does not certify compliance. https://dampapp.pro/minimum-standards-rented-accommodation-ireland - **Global housing & habitability standards (general):** minimum-standards and habitability regimes for rented and residential property exist across the US, Australia, Ireland, Canada and other jurisdictions. DampApp Pro's offline psychrometric calculations and structured photo evidence can support damp and mould documentation under such regimes generally.