research into the problems caused by driving rain on exposed solid stone buildings damp towers...
TRANSCRIPT
Research into the problems caused by driving rain on exposed solid
stone buildings
DAMP TOWERS PROJECT
English HeritageUniversity of OxfordSheffield Hallam UniversityColin BurnsRidout AssociatesArchitects and Contractors
This talk
• water penetration
• potential remedies
• climatic futures
• the research project: site testing and monitoring
laboratory simulations
results
Questions to answer
• how does driving rain enter solid masonry?
• how does water, moisture, vapour move within solid masonry?
• what difference does wind pressure, humidity, time, temperature make?
• are there differences in types of rain?
Questions to answer
• what are relative differences between remedial treatments?
• are there examples of similar towers performing differently
• which treatments work best?
• to what extent are human faults responsible for performance?
Wall 1
Smooth Render
Wall 2
Weatheredjoints
Wall 3
Coarse finished render
Wall 4
Repointed with OPC
Wall 5
Control
Results of Phase 1
• walls built with cement wetted up quickest & dried out slowest
• walls built with hydraulic and non-hydraulic lime mixes gave similar results
• walls built with hydraulic lime renders took longest to wet up and dried out quickest
Run 1Run 2Run 3Run 4Run 5Run 6
Start date03/08/200416/09/200409/05/200504/10/200524/01/200602/05/2006
TestingWalls 1 & 2 as builtWalls 1 & 2 as builtRendered walls 1 & 2, walls 3 & 4 as builtWalls 1,2 ,3 & 4 all renderedWalls 1 & 2 plastered, walls 3 & 4 renderedWalls 1 & 2 plastered, walls 3 & 4 grouted & un-rendered
Tentative Results from Phase 2
• whole of the wall acts as a system
• saturated walls without voids do not discharge water on the inside face
• walls with voids do discharge water on the inside face
• size of voids does not seem to make any difference
Tentative conclusions
• render is very effective at reducing water intake in voided walls
• lime putty render takes on more water but dries faster than hydraulic lime render
• grouting very effective especially for large voided wall during prolonged rain
• grouting only effective when voids filled
• plaster effectively reduces rain penetration
Application to lighthouses
• understand the problem
• treatments depends on building & problem
• building needs to be considered as a complete system
• use traditional materials
• controlling indoor environments
• maintenance and monitoring