CEILING FRAMES Created by Michael Martin March 2004 / Revised Feb 2007.
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Transcript of CEILING FRAMES Created by Michael Martin March 2004 / Revised Feb 2007.
CEILING FRAMES
Created by Michael Martin March 2004 / Revised Feb 2007
• Reference General Construction Knowledge Section 7 – Construct Ceiling Frames (from P278)
• The ceiling frame is the horizontal area between the top of walls and the roof
• Consists of ceiling joists,trimmers, hanging beams and counter beams
CEILING JOISTS – P279• Joists carry the ceiling sheets and provide a
lateral tie between base of opposing rafters
CEILING TRIMMERS – P279-80• Sometimes called trimming joists, short
lengths at right angles between ceiling joists. Give fixing to ends of ceiling sheets and can provide fixing for internal walls.
HANGING BEAMS – P280,81• These provide support to the ceiling joists
mid-span, must be blocked at ends and if large sections may need to be strapped
Trimmers
Ceiling Joists
Hanging beam
SUPPORT TO JOISTS – P280• There are three common types of support
between ceiling joists and hanging beams, joist straps, triple grips and ceiling dogs
Remember:
Hanging beams go above the joists, so we have to block the ends. see page 281
CUTTING HANGING BEAMS P281
• Where hanging beams run across ceiling joists with end protruding past the rafter line as in a hipped roof, they must be cut but also supported via a trimmer
COUNTER BEAMS – P282• Counter beams run at 90deg. To the
hanging beam and supports it when it’s length exceeds it’s allowable span, ends of counter beams are packed slightly to allow for deflection.
SET OUT & ERECTION OF FRAME – from P283
• GABLE ROOF• the set out of the ceiling frame is based on the
set out of the rafters• First check top plates for straight & square• Mark position of gable end rafters• Then work from one end, set out position of
common rafters, other side of line becomes joists
• See sketch
• Next cut all ceiling joists to length and fix into position, double skew nail
• Cut and fix ceiling trimmers to ends
• Cut and fix trimmers above internal walls where required
• Lastly fit hanging beams to the centre of the ceiling joists length over each room as required
• Remember fixing and blocking for hangers
REVIEW ON WORKSHEET• Review this part of your text book
• In your own words answer the questions on your worksheet
REVIEW ANSWERS TO WORK SHEET
Purpose of frame….
Designed to enclose the room, keep it free
from dust and it also provides insulation and
Security
Function of ceiling joists…
The horizontal member that carries the load of
the ceiling sheets and act as a tie between the
rafters at their base
Function of trimmers….
To provide fixing for ends of ceiling sheets,
also internal walls where they fall between
joists and help give lateral stability to frame
Function & position of hanging beams….
To support ceiling joists mid-span, must be supported on load bearing walls & blocked at ends
Fixing to hanging beams by….Joist strap, triple grip, or ceiling dog and should be fixed alternate sides at every
secondjoistHanging beams at external wall ….
Trim hanging beam to pitch of rafterFunction of counter beams….
Run 90 deg. to hanging beam and provides
support to them where they exceed their own
span
Set out and erection…• Check top plates are straight and square• Mark gable end rafters at each end• From one end set out common rafters marking
each side of line for (r) rafter and (j) joist• Cut joists to length and fix into position, double
skew nail• Fix trimmers to ends and where required for
internal walls• Fix hanging beams to the centre of joists length
in rooms required• Provide strapping where required