External Envelopes Flashcards
What is a mortar formed from?
A mixture of cement, lime, sand and water
What sets out mortar classifications?
BS 998-2 Specification of mortar for masonry
What is the minimum heights and laps for a DPC?
150mm above ground level. Lapped by at least 100m adhesive sealed and continuous with DPM.
What are the primary functions of a DPC?
resist moisture penetration from below (rising damp)
Resist moisture penetration from above
Resist moisture penetration horizontally
What is the primary function of a DPM
Prevents moisture entering from floor below
What are some common DPC materials?
Historically:
- Lead
- Bitumen
- Slate
- Engineering bricks
Today:
- Low density polyethylene
- bitumen
- polypropylene
What is the spacing of movement joints in a brick wall?
Every 12 meters
What are the functional requirements of external walls?
Strength and stability
Weather resistance
Sound insulation
Thermal insulation
Fire resistance
Durability
Appearance
What types of non-load bearing external wall are you aware of?
Curtain walling
Rain screen cladding
What is curtain walling?
Curtain walling is non-load bearing cladding which separate the interior from the exterior of a building, typically formed of a lightweight aluminium frame with glazed in-fill panels.
What is rainscreen cladding?
A rainscreen is part of a double wall construction, It is comprised of an outer skin of panels and an airtight insulated backing wall separated by a ventilated cavity.
What is cladding?
Cladding is components that are attached to the primary structure of a building to form non-structural, external surfaces.
What is structural glazing?
A structural glass wall is a minimal and modern alternative to framed curtain walling, used to create a large or long elevation of glazing where the glass is the primary design feature. The result is a large glass elevation with no visible framing or fixings
What is the difference between rainscreen cladding and curtain walling?
Rainscreen cladding is part of a double wall construction, whereby there is an outer skin of panels fixed to a load bearing external wall with a ventilated cavity between the two.
Curtain walling, whilst also a form of non-load bearing cladding, typically forms and integral part of the external envelope with glazed glazed panels supported by lightweight frame.
What is the spacing for wall ties in a cavity wall?
The maximum horizontal spacing is 900mm, whilst the maximum vertical spacing is 450mm, sitting at least 50mm onto each wall leaf.
What is the spacing for movement joints in brickwork and block work?
Brickwork = every 10-12m
blockwork = every 6m,
What are the dimensions of a brick?
H 56mm
W - 215mm
Depth - 102.5mm
