Tips-A2Z home page


Sub-categories

Bracing (6)
Ceiling (4)
Doors (1)
Fasteners (10)
Flooring (3)
Roof (9)
Storage (3)
Verandah (1)
Walls (6)
Windows (2)

Category  |   Discussion (0)Timber (General)

Main > Building & fixing > Building > Timber
Selecting fallen-down trees for building posts: the heavier, drier, and denser they are, the better. Some timbers can be placed in the ground, and be debarked, whereas others will rot or grow fungi if so treated.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Choosing structural timbers: for bearers and joists, laminated veneer lumber (LVL) is straighter and stronger than normal dried dressed timber. This means it is easier to get the base of the building level, and bows and bumps don't need to be planed off before cladding the floor.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Sorting: When timber is delivered, sort it into types (e.g. bearers, joists, studs, plates, rafters, beams, etc.) and stack in ordered piles on piers off the ground, with airflow around all timber members. Ensure the bowed edge is weighted down and all bows are aligned. Leaving timber unweighted will cause the timbers to dry according to the coil of wood-fibres, and warp fixedly.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
Wall junctions: There are two parts to securing a wall junction:
(a) One wall ends with two studs which are one stud-depth apart, sandwiching a couple of packers at 1200mm spacing. So, if studs are 90 x 35mm, then the gap between the two studs is 35mm, filled by a couple of short packers. The packers must be placed at the adjoining wall end. The adjacent wall end's stud is nailed to these packers.
(b) Lap joins at the wall plates, whether for internal partition walls or for external wall corners.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
Raising walls:
  • For easier handling, create shorter wall sections, and lap-join the top wall plate over a stud.

  • Hardwood wall frames are very heavy, and even heavier when clad with sheet bracing. Leave the plywood sheets off until erected. This might be required anyway, if adjoining partition walls need to be affixed directly to the internal side of a wall frame.

  • Attach the galvanised strap tie-downs temporarily to both bottom and top plate, since you won't be able to slide it underneath after the wall is erected.

  • Screw stopping blocks at the outer edge of the wall, to the joist or bearer, to stop the frame sliding off the edge of the building.

  • Ask another person to help erecting the wall and to hold it plumb (90° to the horizontal) while temporary bracing is secured.

  • To stop the frame sliding while being erected, drive a nail diagonally through the bottom plate towards and into a supporting floor joist. The nail will bend ninety degrees when the wall is upright.
   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
Joining wall plates: Never join top plates over an opening like a window or door.
1. Top plates are butt-jointed either:
(a) over a wall stud, with a connector plate across the joint, over two skew nails, or
(b) between two wall studs, strengthened by two nail-laminated noggings under the plate ("double nogg"), the same width as the top plate, with 3/3.05mm nails either side of the butt join above, and 2/3.05 nails from either side of the noggings.
2. Bottom plates are butt-joined over solid support, like a rim joist or rim block, which is firmly secured to the joists.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof
Ridge beam vs. ridge board: These are very different treatments to the apex of the A-frame, and should not be confused.
- A ridge beam is a hefty structural member, like 300 x 100mm, that supports the weight of the rafters, sitting at the peak of the A-frame underneath birds-mouthed rafters that rest on top of the beam. It should be one whole length, but if joined the joints of a ridge beam must be made over a support.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
Image of floor joist rim block: Bottom plates are butt-joined over solid support, like a rim joist or rim block, which is firmly secured to the joists.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof
- A ridge board is a smaller timber like 190 x 35mm, which does not carry the weight of the rafters but provides a connection for them. The weight of the roof pushes out at the bottom of the rafters, so they must be coupled to ceiling joists and be tied with collar ties in the top third. It may be joined in the very centre, between rafter pairs, without requiring a support.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof
Rafters: Getting the angles right is important for structural strength and lack of movement. Create a template rafter with the angles of the plumb cut against the ridge board, of the birdsmouth against the wall top plate, and of the end where the fascia board will be affixed. Using dressed timber makes this process much easier.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof
Erecting the ridge beam on gable roof: Temporarily fix two vertical timber studs, longer than the roof height, at either end of the ridge beam position, with a short stud placed placed nearer the top for the ridge board to rest on. Screw the ridge board to these two studs. Then place the rafters.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Delivery charges: Generally, lumber over six metres will need a crane to unload, increasing delivery charges substantially. To avoid this, opt for shorter lengths and join the timbers.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Joins: It is better to avoid joining runs of structural members, and use whole lengths instead.

Some standard structural joints of dressed timbers:
  • Butt: The weakest type of join, where two ends meet along a straight line or at right angles. Butt-jointed timbers in a straight line need extra securing, e.g. with a cleat.

  • Cleat: For securing butt-joined wall plates, joists, or ridge beams, preferably in non-loadbearing sections. The cleat is a piece of timber the same depth and width as those to be joined, is nailed to both, like a bandaid on skin.

  • Scarf: Like a butt join, but the cut is diagonal rather than at a right-angle to the length. A bolt can run through both timbers across the join. The cut can be on a horizontal or vertical plane relative to the timbers, depending on whether the securing bolt runs horizontally or vertically through the timbers.

  • Lap / Splice / Halved: The two pieces of timber overlap, either in a straight line or on a right-angle. Each lap is nailed or screwed to the other. This is a stronger type of join than those above. This is a typical strengthening joint at wall junctions at outer corners and sometimes partitions, and is seen in both the top and bottom wall plates.

  • Mortice and tenon: tab into slot, often used with doors and windows, or with greenwood poles and secured with wooden dowels.

  • Half check: A horizontal lap join, more suitable for bearers. A single bolt can run vertically through both laps, or a bolt to each timber separately, so long as a nail plate holds the two pieces together.

  • Notching: This technique of supporting studs inside chiselled-out notches in the wall plates has been succeeded by better bracing and tie-downs.

   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber
Joining bearers: Avoid joins where possible, and only where fully supported by a stump or other support. Bearers must be anchored to all stumps, by for example hot-dipped galvanised bolts, hoop straps, steel rod, and so on.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Nailing structural members: with a hammer, toe-nail (aka skew-nail) 75mm x 3.15mm nails. Framing nail-gun nails used in the same way can be slightly smaller, e.g. 2.3mm diameter.

Securing fasteners with nails: 35mm x 3.15mm if using a hammer, otherwise 32 x 2.3mm for a gun.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Before securing structural members, make a test to see if the nails split the timber. If this happens, pre-drill a hole 4/5 the diameter of the nail.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Bolt holes: Structural members secured with a bolt need the bolt-hole to be drilled 0.8 - 1.5mm larger than the bolt diameter.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Securing floor joists: Toe-nail the joist at every crossing over a bearer. This entails two nails at maximum 45° (no less than 30°) from the horizontal, at either side of the timber.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Prevent splitting timber: Blunt the nail to crush wood fibres rather than splitting them. Also, try dipping the nail in some oil or wax. Or, predrill a hole 4/5 diameter of the nail.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
Plywood sheets or galvanised strip bracing can be used. Ply sheets, if secured properly, also act as tie-downs of the studs to wall plates.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Storage
Be careful to cover timbers to avoid sun, rain, wind and earth contact, before and after they are installed. This helps prevent shrinkage, swelling and rotting.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Storage
Trees can be stored outdoors and last a long time, but trees are alive. Timber stored uncovered outdoors will usually disintegrate, sometimes rapidly.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Galvanised fasteners: these are flat or multi-plane plates for attaching structural timbers more strongly than using just nails or screws. They can be as simple as nail plates, which have teeth, and are often used for roof trusses, or as complex as gang-nail multi-grips, which can secure rafters to both top wall plates and adjoining ceiling joist, and secured with 4 x 2.8mm diameter nails per plate end.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Nail holes should be 8 times the nail diameter from the nearest timber edge, typically >16mm.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Tie-down straps: If using strap bracing, these 30mm wide strips of galvanised metal are "tie-downs" that hold the studs to the bottom and top wall plates, or rafters to the top wall plates. There is generally one strap every 1200mm along the wall plate (at top and bottom of the wall). The strap should reach a minimum of 250mm along the stud on both its sides.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Fastening tie-down straps: Use 5 nails per end if using a hammer, or 6 if gun-driven.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Windows
Window openings: Timber shrinks as it dries, even if it is kiln-dried. This reduces the size of the window opening slightly, and can put pressure on window glass. The window opening should be up to 10mm on all sides larger than the window (including reveals).   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Levelling: For bearers, choose to install the two outermost bearers first. Erect a very taut string line as a levelling guide of the top of the first bearer. After securing this bearer, do the other outermost bearer in the same way. Then run string lines between both bearers to guide the levelling of all intermediate bearers.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Fasteners
Nail-laminating: For added strength, timbers like bearers are bond-nailed together, along the same principle as two match-sticks held long-wise together are stronger than a single one. The grain / rings are to be in opposing directions to counteract warping. Nails are skewed and staggered at a distance of twice the timber width, and an additional nail added at load-bearing positions.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Cogging: Measure floor joists to check they are all the same width. The narrowest width is the standard. Wherever all other joists cross the bearer, they are cogged, which is to chisel off excess at the bottom edge supported by the bearer. This ensures the floor is level.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Flooring
Platform floors vs. built-in floors: A platform floor has the floor boards or sheets installed before the walls, so that walls sit on the floor platform. Built-in floors have the wall-plates sitting directly on the floor joists, and the floor boards added after the walls and roof are finished.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Flooring
Built-in floors: The roof needs to be finished, walls clad, and doors and windows installed, before installing floor-boards, or else they need to be very well protected from rain to maintain a moisture content of about 12%. Also, the doubled end floor joists of built-in floors are separated and not nail-laminated together as for platform floors. They are separated by packers, 22m wide for external walls, and 45mm wide for internal partition walls, to create the ledge to nail down the ends of floor boards.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Cutting scheme: Ensure the timber order is specified so you have enough of the right lengths. Of stud timbers, first cut standard studs, then trimmer studs (for either side of windows and doors, supporting the lintel or header timber), then sills, then jack studs (sitting above and/or below the window and door openings), then standard noggs, then smaller odd noggs. Leave bowed timbers for noggs.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
Ply bracing needs to be fastened a minimum of 7mm from the panel edging.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Bowed pieces of timber should be placed with the bow upwards so that any weight on it helps to straighten it.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber
Preserving timber: The cut ends are like masses of tiny straws, sucking up moisture. For this reason, lumber ends should always be covered by other timber, or capped with metal, or painted.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
General Tips for Joining Wall Plates:
- It is better to avoid joining wall plates on long stretches with no intermediate wall partitions or external buttressing. Even short lengths of wall (<1m) will push outwards or inwards at the top plate.
- If joining wall plates in several places along a wall, the outwards force of the rafters will be increased, so it is advisable to use ceiling joists to tie the top plates together.
- If choosing option (a), the supporting wall stud is installed after erecting the new wall frame alongside the existing wall.
- If choosing option (b), ensure any shoulder jacks or studs adjacent to the double-nogg's stud are not installed until after the latter is secured.
- When nailing the double-nogg in place, you will need a ladder or scaffold. Try to avoid leaning against the top-plate, as this will push the butt-joints out of alignment. Use clamps to hold the double-nogg in place while pre-drilling and nailing.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
Installing plywood sheet bracing:
In smaller wall areas, especially where plumbing and electrical lines will be installed, it is better to erect and plumb walls first. Then mark on the walls where plumbing pipes and conduits will be installed. Install noggs to support sheet bracing around these access points, then install the sheet bracing, leaving the access points unclad. Later, after plumbing and electrical work is finished, the final pieces of bracing can be secured.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Ceiling
Nailing ceiling joists:
- First secure the ladder well.
- Use strong metal clamps to hold the joist in place when nailing.
- Hammer towards the body, with one foot against the joist and the other on ladder rung.
- If using multigrips, nail the horizontal tab to the top wall plate first, then the vertical tab to the top wall plate, and finally the last vertical tab to the ceiling joist. If skew-nailing, pre-drill and oil the nail.
- If a rafter will be installed against the joist later, don't leave nail heads protruding on that side.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Ceiling
Use ceiling joists to tie the top wall plates together, against the outward force of the rafters.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Ceiling
Use ceiling joists to help stabilise top plate movement on either side of wall joins.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Windows
For evenness of appearance, the tops of windows are placed at the same distance as the tops of doors, from the floor. This point is very slightly below the eaves lining, which rests on the window and door heads (upper reveal).   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
Wall insulation batts are fitted before sheet bracing is complete.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Walls
Notches: Notches are shallow cuts or checks into wall studs, to embed window head trimmers and bottom trimmers more securely. They extend a maximum of 10mm or a quarter the breadth of the stud, whichever is less. Placing a nogg on the outside is good building practice. Also, a checked window head trimmer can act as a lintel in a non-loadbearing wall, so long as the opening width is no more than 1200mm.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof > Safety
Taking roofing equipment up: Don't carry equipment when climbing a ladder, but keep hands free for holding to rungs and rails.

General tips:
- Use a tool pouch on a belt for carrying a hammer, tape measure, pencil, nails and mobile phone with you at all times.
- Install a couple of temporary, sided platforms on the ceiling joists for holding equipment: boxes of nails, framing gun, nail oil, plans, bottle of water, snacks, sun lotion.
- Alternatively, use buckets hung around the roofing area, or secure tools to studs using short bungee cords. Power drills can also be secured to one's belt.
- Transfer equipment to the roof by placing it in a sturdy bucket and hauling it up by a rope.
- Transfer an air framing gun to the roof, then connect it to the hose, then pressurise the hose.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof > Safety
General roofing safety tips:
- Choose calm, clear, cool weather for roofing.
- Never work on a slippery, wet roof.
- Use rubber shoes with dry, clean soles.
- Keep the roofing area clean of dirt, mud and debris.
- Always move hoses and extension cords out of the way of one's feet.
- Wear sunglasses, hat, and full skin cover.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Roof > Safety
Using a roofing harness:
- Where it is possible to fall 2m from a roof, use a full body harness (a personal fall arrest system) and not a waist belt.
- First create a slide guard near the edge of the roof, by installing roof brackets every 4' on the top surface of rafters, within 18" of the eaves, and placing planks along these brackets.
- Second, attach roof anchors over the ridge beam and secure by hammering (not shooting) nails into two opposing rafters. The roof anchor should be at least 2m from the edge of the roof.
- Ensure the body harness is snug, and has D hooks on front and back of the body. A short 1m lanyard, with energy / shock absorber, is hooked onto the body harness with a locking carabiner. Its other end has a spring-loaded clutch that slides along a rope, which in turn is secured into the roof anchor.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
Fastening plywood structural bracing:
50mm spacing along top and bottom wall plates, and on horizontal butt joints; 100mm spacing along vertical edges; 150mm spacing along intermediate studs. Leave a 2mm expansion gap at butt joints between adjacent sheets.

- They are prone to warping and then are impossible to fix properly. Store completely flat and with flat sheets on top to stop curling and warping, or install immediately and completely.

- Never leave plywood bracing fixed incompletely to stud walls!   kellyjones00 (593)
 
 

– –– ——— –– –

Main > Building & fixing > Building > Timber > Verandah
A verandah also acts as wall buttresses, assisting in resisting rafter force, and, if the roof slope is flattish, as scaffolding while building the main roof.   kellyjones00 (593)

– –– ——— –– –

Main > Building & fixing > Building > Timber > Bracing
If plywood sheets are too short: If the walls are higher than plywood sheets, and a small piece is required to clad the entire frame, then put the full piece below and the small piece at the very top. Any rain that soaks into the ply sheets drains and collects at the bottom. A full sheet at the bottom means less exposed ends to warp.   kellyjones00 (593)
 
 


Click to enlarge

– –– ——— –– –


«  <   1   2   >  »

 


 

To post a new tip, sign up for a free account.
(Unfortunately this is a necessary spam prevention measure)

Who is online
In total there are 3 users online :: 0 registered and 3 guests (based on users active over the past 5 minutes)