BT5 Module 5 (Tilt-up) & 6 (Skylight)

"A type of building and construction technique using concrete, where the process resembles barn raising specifically and wood platform framing generally."

Tilt-up

In this method, modular concrete elements (i.e. walls, columns, structural supports, etc.) are formed on a concrete slab; usually the building floor, but sometimes a temporary concrete casting surface near the building footprint

Tilt-up

In tilt-up construction, the elements are tilted from _____ to ______ with a crane and braced into position until the remaining building structural components

horizontal to vertical

T/F: In tilt-up construction, studs, gussets and attachment plates are located within the form for embedding in the concrete

TRUE

T/F: Concrete elements can also be formed at factories away from the building site.

TRUE

Difference of tilt-up from prefab

Moulds are designed for a specific building and usually not reused

Walls are created horizontally in large slabs of concrete called panels. The panels are then lifted, or tilted up, into position aaround the building's slab.

Tilt-up

In tilt-up, the forms are usually anchored to the casting surface with ____, or otherwise adhered to prevent damage to the floor slab

masonry nails

T/F: In tilt-up construction, a high quality plywood or fiber board that has at least one smooth face is typically used as the casting surface, although aluminum or steel forms are also frequently used.

TRUE

A __________ is sprayed on the form's surfaces to prevent the cast concrete from bonding with the form or slab, allowing the cast element to separate from the casting surface once it has cured.

chemically reactive bondbreaker

T/F: There are no rebar grids required inside tilt-up construction forms.

FALSE

A rebar grid is constructed inside the forms, after the form release is applied, spaced off the casting surface the desired distance with...

plastic "chairs" or dobe blocks

5 steps: tilt-up construction

1. Build forms on casting surface 2. Spray chemical bondbreaker 3. Construct rebar grid 4. Pour concrete 5. Remove forms then tilt into place

Where space is at a premium, on many sites the concrete slabs are cast one on top of the other.

Stack cast

T/F: If there is a lack of space on site, the concrete slabs may be cast one on top of the other

TRUE

used to hoist the wall slabs to a vertical position

Cranes

Previously used to hoist the wall slabs to a vertical position before cranes

Tilt tables

In tilt-up construction, the connections to the roof and floors are usually ______ that were secured into the forms prior to concrete placement

steel plates with headed studs

T/F: Tilt-up construction does not save on construction costs

FALSE

T/F: Tilt-up construction can be used to compress the construction schedule

TRUE

Adds light, view, and, in some cases, ventilation, without affecting privacy or taking up wall space.

Skylight

The difference between a roof window and a skylight depends on...

accessibility

If you can reach it directly from the floor, it's called a _____, whereas if it's inaccessible, it's called a ____

roof window; skylight

Types of skylight accdg to use (3)

Skylights for light, for view, for ventilation

In the Northern Hemisphere, a _____-facing skylight with clear glazing brings a great amount of light and heat, but it may produce glare

south

In the Northern Hemisphere, a _____-facing skylight can create soft lighting

north

Skylights with clear, translucent, or tinted glazing allow you to enjoy view overhead

Skylight for view

General rule of thumb for determining skylight area

1 sqft. of skylight for every 20 sqft. of floor space

T/F: Light shafts can be straight, angled, or splayed

TRUE

the skylight sits directly above the ceiling opening

Straight light shaft

The skylight is positioned off to one side of the ceiling opening

Angled light shaft

The ceiling opening is larger than the roof opening

Splayed light shaft

T/F: Most skylights do not come with flashing systems that seal the roof effectively

FALSE; comes w flashing

2 types of skylights

Curb mounted, Framed in place

Type of skylight that is raised above the plane of the roof;

Curb-mounted

Type of skylight which either sets on a wood frame curb or the curb is an integral part of the unit

Curb-mounted

Type of skylight installed flush with the plane of the structure, much like a vertical window. It is held in place with L-shaped brackets

Framed-in-place

Sits nearly flush with the surface of the roof. It is set in the opening rather than over it and held in place with steel brackets

Framed-in-place

Difference of the flashing of curb-mounted vs framed-in-place skylight

Curb mounted has 2 side flashing, while framed-in-place consists of a series of step shingles that match the 5" exposure of each row of roofing

The roof opening is framed with ______ - framing lumber run horizontally across the opening, securely nailed to the rafters to support the structure

headers

T/F: Ceiling headers should be the same size as the ceiling joists.

TRUE

A skylight framing assembly consists of (3)

the roof opening, the light shaft and the ceiling opening

May be opened to allow air to pass through. These skylights are ideal for bathrooms and kitchens, where they help to relieve excess moisture and keep the flow of air steady

Ventilating skylight

Any type of skylight which doesn't open. This type of skylight is intended solely to allow light to pass into the house.

Fixed skylight

Essentially a very small skylight, intended mainly for hallways and small rooms where a traditional skylight wouldn't easily fit.

Tubular skylight

"The most common skylight style, consisting of a square or rectangular piece of flat glass or acrylic, which may be fixed or ventilating"

Flat skylight

A ___________ emerges from the roof as a half-sphere bubble.

Round skylight

A _____ peaks up out of the roof with a number of glass or acrylic polygons -- these skylights are considerably more expensive than simpler models, but are also very aesthetically impressive.

polygon skylight

A simple four-triangle pyramid which juts out of the roof.

pyramid skylight

is similar to a flat skylight, except that the glass rounds up past the surface of the roof

dome skylight

The two main materials used to construct a skylight are

Glass and acrylic

If your skylight will fit between existing rafters, use _________

single header

If you have to cut a rafter when installing the skylight, use _____________

double headers

A long rectangular skylight which peaks up above the roof surface to a central ridge, with a sloping triangular piece of glass on either short end

Hip ridge skylight

A simpler version of the hip ridge, with two long triangles sloping in towards one another, and straight triangles closing off either end

Ridge skylight

"A simple slope skylight which rises from the roof of one story and ends by leaning against an upper wall of the next story"

Lean to skylight

A more complex form of the lean-to, which consists of a half-sphere against an upper wall, often seen in large arboretums

Barrel vault skylight