Framing

                  steel beam

             joists attached to wood ledger bolted to bottom flange

             joists cut back and scabbed across the top 

             with 12 mm space for shrinkage under scab

-joists butting into a steel beam must sit on a wood ledger and have a scab across the top joining the two joists the scab must have a 12  air space to allow for joist shrinkage

-or wood ledger bolted to beam and joists nailed to ledger with full bearing on top of beam

-steel beams W or S .. w indicates wide flange...the first number is the dimension of the depth and the next number is the weight in kilograms per metre

-steel beams I or wide flange if using wood plate wood plate on bottom flange it must be bolted on  6.3mm diameter bolts  at 600 centres

framing

start from one corner of building and ensure all framing starts from this designated corner, 

Floor framing members... detailed views

I joist truss

floor system IJ's are a great system for long spans..great for large rooms without bearing walls...

the IJ shown does not show the rim joist ... I glue the bottom of the joist to the mud sill an use two nails one of each side of the bottom chord

I use a plywood stiffener one on each side of the web at each end of IJ .. through nails and clamp off nails the stiffener has about half an inch gap at top 

I use squash blocks both sides of IJ they are about a sixteenth of an inch taller than IJ at all load bearing walls 

When you add rim board (not shown) through nail ...one nail into each top and bottom chord

Rim board is toe nailed into plate one nail every 300  

When using joist hangers keep the IJ back from the flush beam at least 1/8 of inch and a dab of glue between hanger and bottom chord 

When sheathing nail and glue plywood..IJ are designed to have a solid ceiling like Gyp rock applied if no gyp rock strap bottoms with1x4 at 6 ft centres

Nail plywood 5/8" t and g 150 on edge and 300 in field ...use deformed nails...and 1/4" continuous bead of glue

Note squash blocks and IJ blocking when carrying a shear wall or load bearing wall above

a non load bearing wall above just need stiffeners..although I like to use both a stiffener and a squash block

If you are cantilevering the IJ system use a 5/8" sheet plywood reinforcement BOTH SIDES nailed with 62 (2.5") nails every 150 (six inches) into the bottom and top chord  ...MAX CANTILEVER 2 FEET/ 600MM EXTENDS BACK INTO BUILDING MINIMUM 4' /1200MM

sub-floor

-use a panel floor overlay minimum 6  mm when you have a lumber sub floor or a panel sub floor with unsupported edges.. . use: hardboard, plywood, wafer board, particle board nails 22.. staples 28

-joints should be offset by 200 from sub-floor

Construction

types of beams:

Paralams are strands of lumber glued and pressured together... as below

Timberstrand is like many layers of oriented strand board laminated together... as above

Laminated veneer lumber aka LVL are like many layers of plywood laminated together

-solid timber

-glue laminated

-veneer laminated 45 thick..  lightweight..  free from shrinkage..  and defect free..  longer spans

-strand laminated long wood strands bonded and cured under pressure microwave energy

-built-up crown side up bolted together or nailed double row of 89’s at 450Cf.. .quarter point closest to column can have join  at quarter point  (150 variable) see  diagram above

-89 minimum beam bearing

-steel beams I or wide flange if using wood plate wood plate on bottom flange it must be bolted on  6.3mm diameter bolts  at 600 centres

Calculating beam size: number of floors, supported joist length 1/2 each side..  spacing of columns..  use beam tables

-wood beams in concrete need a 12 mm air space unless treated lumber is used

-steel beams W or S .. w indicates wide flange...the first number is the dimension of the depth and the next number is the weight in kilograms per metre

-pony wall may carry joists.. laid out at 400 first is 380..  bottom plate pre drilled for anchor bolts, pony wall does not give any lateral strength 

-layout should always start from one corner for the whole building.. joists..  plywood floor.. stud walls..  rafters.. wall sheathing..  roof sheathing

Construction

bridging

- cross bridging 38x38 or strapping with 19x89 at 2100 centres - strongest is both cross bridging and strapping under cross bridging with 19 by 89

-cross bridging pieces should not touch each other..will squeak, cross bridging should be cut short so they do not extend past joist depth

-the bottoms of cross bridging pieces are not nailed off until house is completed

-strapping..nails two 57’s per joist

-blocking is done alternate sides of a chalk line

-metal bridging done after sheathing

-bridging and blocking should be tight and secure

Construction

columns

-minimum wood 140x140 (186 diameter) must be as wide as the beam they support or have a steel 7  mm plate saddle to support the beam

-steel columns must be 73 diameter, wall thickness of  5 mm and a steel cap at each end (telepost)

-concrete columns must be 200 square or 230 diameter with metal saddle

-damp proofing must be used between wood and concrete post if post is more than 150 below grade

Joists types:

-lumber

-manufactured plywood web joist called  I joists or I trusses  aka  IJs

-steel truss

Numbers:

Floor joists nailed to plate with three 82’s

over lapped at beam nailed each end with two 76’s

-header joists must have five 82’s or three 101’s at trimmer joists and tail joists

-double headers and double trimmers must have two staggered rows of 76’s at 300 centres

-or metal hangers

-floor joists must have a bearing of 38

-over lap joist must not overlap beam by more than 300

-joists butting into a steel beam must sit on a wood ledger and have a scab across the top joining the two joists the scab must have a 12  air space to allow for joist shrinkage

- boxing joists should be of the same size as joists and ends should land on an end of a joist

-layout joists positions on the boxing joist from the longest straightest wall.. offset overlapping joists.. .make sure that first joist space is 20 smaller so that the plywood will fit the spaces on center.. .always offset towards the starting point so that the sheathing fits.. .lay out on the boxing joists openings for stairwells, chimneys, partition, plumbing fixtures

- non bearing wall supported by blocking between two joists 38x89 at 1.2CENTRES

-check bathroom layouts to ensure the joists are not blocking soil pipes if blocked install headers and tail joists .. headers  should be doubled if they exceed 1200. trimmer joists doubled when the length of header joist exceeds 800, if head joist exceeds 3200 it must be calculated for size, if header joist exceed 2000 the trimmer joists must be calculated for size

stairs

stairwell opening..  first trimmers to first headers  with five 82’s..  first headers to tail joists with five 82’s (I USE HANGERS..) first headers  and second headers with 82’s, first trimmers to second headers five 82’s..  nail second trimmers to first trimmers with 82’s spaced at 300 CENTRES

-first headers..  tail joists.. second headers..  second trimmers.. second  joist

-joist hangers or ledgers used with flush beam

-joists embedded in concrete foundation wall must have 2/3rds of their depth buried, ends should be treated with preservatives

Construction

numbers

sheathing

( if you use lumber lay at 45° degrees to joists)

-tongue and groove 5/8" plywood  (should use)

-grain across joists.. lay ply wood  90 degrees to joists

- glue and use ring nails driven well below surface .. screwing and gluing popular screws must have same shear strength as nails

-offset seams start...second row with half sheet

-T&G snap a line.. . bead of glue.. . stay back 50 from snap line with glue.. . place T&G on edge by glue. place grooved edge by chalkline.. . drop to land in position.. .line up.. .tack corners.. .nail to code 150 on edges 300 in field.. .leave grooved side nails loose so next sheet can be eased in.. do whole row.. start second row with partial sheet.. .push in by hand try not to smear glue bead.. .sledge hammer and long  block to fit tightly

-edge nail 150 field 300

-minimum thickness of sub floor with 400 centred joists is 15.5.. 600 centres 18.5

Construction

subfloors

-plywood oriented strand board, wafer board, shiplap, t and g lumber

-lumber no wider than 184 and 19 thick use 51’s two per joist

square edge panel blocked with 38 x 38

-panels nailed 150 edge 300 field, ringed nails

Construction

of access floors

offices, computer and electrical running under floor for ease of assembly and ease of access

-floors are steel frames with removable panels covered withh resilient flooring or carpets

-floors are adjustable for height