Timber Post-Beam Connection
This detail I have been researching for a few days looking at construction details, standards and specifications. I have been trying to figure out the detail which will support the timber bearer to the timber post either notching, bolting or fixing. There are numerous ways to connect the elements but the metal brackets are most commonly used connectors in the construction industry.
AS 1684.2 Residential timber-framed construction
PART 9.2 General Connection Requirements
9.4 Nominal and specific fixing requirements
To determine nominal and specification connections the wind speed needs to be determined. As our site is situated in Sydney, Australia. The geographical region is Region A, non cyclonic.
The site terrain category is classified as open terrain including sea coast areas, airfields, grassed with few
well scattered obstructions, such as isolated trees and uncut grass, having heights from 1.5m to 10m. The topography classifcation falls under T3, situated high on the cliffs of the Dover heights.
Wind Classification: N3
Table 9.2
Connection:
Lower storey floor frame to supports requires - nominal (minimum) connection only.
Table 9.4
Minimum fixing for each joint:
Floor framing - Bearer to timber stump/post
4/75 x 3.33 mm or 5/75 x 3.05 mm machine driven nails plus 1/30 x 0.8 mm G.I. strap over bearer and fixed both ends to stump with 4/2.8 mm dia. each end;
OR
1/m10 bolt through bearer halved to stump;
OR
1/M12 cranked bolt fixed vertically through bearer and bolted to stump plus 4/75 x 3.33 mm or 5/75 x 3.05 mm machine-driven nails
-The connection we will use in the project will be the T-Strap which bolts and nails the strap to both the timber post and timber bearer at each joint. The fixing will comply to the nominal requirement for fixing the sub floor frame.
http://homeservices-directory.com/homeowners/tips/beam.html
http://blog.siffordsojournal.com/2011/12/house-update-xi-porch-cross-beams.html
http://www.familyhandyman.com/DIY-Projects/How-A-House-Works/How-The-Structure-Works/how-to-repair-a-load-bearing-post/View-All
2. Bearers
Hyspan timber framing is a structural range of timber elements that are widely used in Australia. To determine bearer sizes and spans the RLW (Roof load width) and FLW (Floor load width) need to be calculated from AS1684.
Bearer A
(17.4m)
= X + Y/2
= 0 + 3/2
=1.5
Bearer B
(17.4m)
=Y + Z/2
=3 + 3/2
=3
Bearer C
(17.4m)
=z/2
=3/2
=1.5
Roof load Width
Wall A
RLW = X/2 + a
= 16/2 + 0.6
= 8.6
Bearer A- Hyspan (supporting upper storey load bearing walls) 300d x 75b
3.9 Maximum Single Span
Bearer B- Hyspan (supporting floor loads only) 300d x 75b
5.3 Maximum Single Span
Bearer C- Hyspan (supporting upper storey load bearing walls) 300d x 75b
3.9 Maximum Single Span
Sketches showing the grid of the posts, Bearer A + C are the same dimensions and are supporting upper loads with 6 posts and footings. Bearer B is supporting floor loads only with 5 posts and footings. All bearers are the same dimensions 300 x 75 Hyspan
.JPG)
More fixings for Post Beam connections
http://www.diyadvice.com/diy/decks/build/install-beams/
http://tamlyn.com/PostBeamCaps.html
http://www.homehardware.ca/en/rec/index.htm/Hardware/Lumber-Connectors/Dimensional/Caps-Bases/4-x-4-18-Gauge-G185-Post-Beam-Cap/_/N-ntjwe/R-I2682250
http://www.finehomebuilding.com/how-to/articles/top-10-deck-building-mistakes.aspx
3. Floor Joists
- Hyspan 240 mm x 45 mm
- 450 Spacing (centres)
- 6.1 maximum continuous span - allowed overhang 1.5 m
On site image displaying Hyspan Timber Bearers and Timber floor joists connected to timber posts.
Floor joists are the next series of members for the sub-floor frame. They are supported by the bearers.
Typically the floor joists run over the tops of bearers, however, they may be attached to the sides of bearers. Like bearers, floor joists may be single span or continuous span.
http://toolboxes.flexiblelearning.net.au/demosites/series10/10_01/content/bcgbc4010a/10_floor_systems/10_sub_floor_framing_floor_joists/page_001.htm
4 Timber Frame construction to skillion roof
I have been researching the Residential Timber frame construction standards to calculate a design that will comply with codes and standards.
-model formwork
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