Flashcards
cavity walls
Cards in this deck (18)
- 17 types of wall construction1- monolithic
2- traditional solid masonry
3- lined
4- cavity construction
5- frame wall
6- panel wall
7- curtain walling - 24 types of monolithic options1-adobe (traditional mud)
2- rammed earth
3-modern monolithic concrete
4- straw bale & hemp - 33types of traditional solid masonry1- solid brick
2- solid stone
3- solid concrete block (rarely used) - 45 lined wall characteristics- concrete structural layer
- rigid insulation fixed to concrete
-external render or cladding
-insulation foil backed (prevent moisture penetration)
-fixings depend of type of cladding - 5cavity wall characteristics-concrete block inner leaf structural layer
-rigid insulation fixed to inner leaf
-air cavity
-outer leaf of brick or block
-most common form - 6advantages of cavitiesthermal break between inner & outer leaf
sound insulation
low tech construction technique
moisture break - 7disadantages of cavity construction1- as insulation requirements increase, cavities get wider
2- timber frame more sustainable
3- poor construction on site results in thermal bridges - 8options for cavity construction- brick or block cavity walls
- full insulation
-partial fill and air cavity
-two leafs of cast in situ conc. possilble but rarely used in ireland - 9principles of cavity walls-concrete blockwork inner leaf
-concrete or brick outer leaf
-wall ties connecting leafs (regular gaps)
-internal finishes w/ plaster/plasterboard
-can be finished externally
-INTERNAL LEAF LOADBEARING - 10full fill cavity insulation-injected or "blown in" after completion of cavity walls
-granular or bead insulation
-difficult to check if insulation has penetrated fully
-increased risk of rain penetration
-not suitable in exposed areas - 11partial cavity fill-rigid insulation fixed to inner leaf
- suitable in exposed areas
-greater resistance to rain penetration
-much more common in ireland - 12problems with cavity walls-greater insulation requirements
- U value of 0.21 required for external walls
-special wall ties needed
-overall wall thickness now 350mm min - 13components of a cavity wall : insulation-rigid sheet insulation used in partial fill (can be cut and scored to accommodate openings
- can prevent moisture penetration (foil backing)
-grandular insulation used in full fill- pumped or blown into cavities - 14types of wall ties
- 15wall ties spacings
- 16jamb and cill details
- 17how to retrofit cavity wallsthe cavity wall is injected with insulating materials by drilling holes in the external wall, through the mortar joint.
-holes and generally 22-25mm diameter.
35% heat loss through uninsulated walls - 18when would retrofitting walls be necessary- dampness occurs
-water transferred across cavity via insulation
Information
- Description
- Flashcards on cavity walls, created by Caroline Flynn on 22/04/2017.
- Created by
- Caroline Flynn
- Views
- 10
- Rating