What is the purpose of wall plates in a roof?
This provides a fixing point for the feet of rafters, and distributes the load exerted by the roof structure down through the walls without creating pressure points where each rafter meets the wall, and also acts to prevent wind uplift . Generally, wall plates are in lengths of not less than 3 m.
How do you connect a wall plate to a roof?
For instance the rafter connection to the plate on the face of the wall could quite easily the "U" shape joist hangers to good effect. If the roof is sat on framed construction then the term wall-plate is not used. Usually the top plates of the wall frame are beefed up and bolted connections from the roof are used via angle brackets.
What size wall plate do I need for a roof?
Wall plates should be: 1 bedded to line and level 2 fixed using nails or straps 3 a minimum of 3m or extend over at least three joists, rafters or trusses 4 joined using half-lapped joints, including at corners 5 38 x 100mm or in accordance with local practice.
What is a platform wall plate?
Platform framing. In platform framing there are three types of wall plates and are located at the top and bottom of a wall section, and the two hold the wall studs parallel and spaced at the correct interval.
What is roof plate?
noun A wall-plate which receives the lower ends of the rafters of a roof.
What is a top wall plate?
The top plate is the upper horizontal framing member of a stud wall. It is typically the same width as the studs and bottom plate and is some type of stress-graded dimensional lumber, commonly 2x4 or 2x6.
What are roof plates called?
purlinA purlin (or historically purline, purloyne, purling, perling) is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin.
Is wall plate needed?
This is an interesting fact and means that wall plates are not a specific requirement of the Building Regulations and are therefore, strictly speaking, outside the scope of a building inspector's remit.May 1, 2020
What does a wall plate do?
This provides a fixing point for the feet of rafters, and distributes the load exerted by the roof structure down through the walls without creating pressure points where each rafter meets the wall, and also acts to prevent wind uplift. Generally, wall plates are in lengths of not less than 3 m.Sep 15, 2020
What is a wall plate and its purpose?
wall plate. noun. a horizontal timber member placed along the top of a wall to support the ends of joists, rafters, etc, and distribute the load.
How are wall plates fixed?
Wall plates should be: fixed using nails or straps. a minimum of 3m or extend over at least three joists, rafters or trusses. joined using half-lapped joints, including at corners. 38 x 100mm or in accordance with local practice.
Do I need a wall plate for a flat roof?
No you didn't need a wallplate in this scenario, indeed millions of flat roofs around the country don't have them as they're not required and a waste of timber.Nov 9, 2020
How are wall plates calculated?
WALL PLATE is the timber/wood that are placed on top of blocks or roof beams as the case may apply, so for the fastest way to calculate this, is to add the entire walls length and divide by 3.6m to know the numbers of pieces you need.
How do you install a wall plate?
8:5212:41How to Set up a Wall Plate - YouTubeYouTubeStart of suggested clipEnd of suggested clipAs i've done there i've marked out the half lap joint every wall plate that laps onto it alwaysMoreAs i've done there i've marked out the half lap joint every wall plate that laps onto it always connects as a half lap joint. So that's the first two and that represents this one here.
How do you attach wall plates?
3 In England, Wales and Northern Ireland wall plates should be jointed with half-lapped joints. Butt joints should not be used but if found should be joined with metal or timber strapping across the joint.
How do you attach a roof to the wall?
0:355:33Roof to wall connection - YouTubeYouTubeStart of suggested clipEnd of suggested clipAs you can see here this truss or rafter sits on the top plate of this wall. And he's connected toMoreAs you can see here this truss or rafter sits on the top plate of this wall. And he's connected to the top plate. By two nails these nails are just shot in on others either side.
What comes next after the wall plates are fitted?
If you know exactly where it needs to go, it might be easier at this stage to trim out the joists to accommodate a loft trap for access into the roof space later on.
Why is it important to get the right wall plates?
Getting the wall plates or top plates as they are sometimes called right is important because all the ceiling joists, roof rafters hips etc. will all be fixed to them.
What can be fixed in the corner after hip and jack rafters?
After the hip and jack rafters are installed more joists or noggins can be fixed in the corner to fix the plasterboard to.
Why do you put ceiling joists before rafters?
The ceiling joists are installed before the rafters as they will stop the roof spreading and also give something for you to lay planks across to stand on when building the roof.
When fixing the wall plates down onto the brickwork, if the building is square/rectangle measure from corner to?
When fixing the wall plates down onto the brickwork, if the building is square/rectangle measure from corner to corner diagonally. When the measurement is equal the plates are square.
Do you put lateral restraint straps on brick?
In the UK they're bedded on sand and cement to lose any discrepancies in the brickwork then fixed down securely with lateral restraint straps, though you might want to wait until you've set out the joists first so you don't put the straps in the way of the joists or rafters.
What is wall plate?
A wall plate is a load-bearing structural member used horizontally and part of a timber framework .
How long is a wall plate?
Generally, wall plates are in lengths of not less than 3 m. As the mortar does not bond the wall plate to the wall, steel straps are used to ensure that the roof structure remains secure. These are typically 1.2 m long with a cranked end and are fixed to the wall plate at 2 m centres.
What is a plate in a building?
A plate or wall plate is a horizontal, structural, load-bearing member in wooden building framing.
Where are the wall plates located in platform framing?
In platform framing there are three types of wall plates and are located at the top and bottom of a wall section , and the two hold the wall studs parallel and spaced at the correct interval. Each type continues in a piecewise fashion around the whole perimeter of the structure.
What is the upper plate on a wall?
Upper wall plate, top plate or ceiling plate — upper wall plate which is fastened along the top of the wall studs, before the wall is lifted into position and on which the platform of the next story or the ceiling and roof assembly rest and are attached.
What is a top plate?
Also called a wall plate, raising plate, or top plate, An exception to the use of the term plate for a large, load-bearing timber in a wall is the bressummer, a timber supporting a wall over a wall opening (see also: lintel ). These are common in Australia.
What is a purlin plate?
Other load-bearing timbers use the term plate but are not in the wall such as crown plate, a purlin -like beam carried by crown posts in roof framing, and a purlin plate which supports common rafters.
What is wall plate?
A wall plate is a very common detail in small to medium-sized buildings in the UK. So common, in fact, that you might expect its design to be straightforward and for any associated guidance to be simple. As with most things, reality is more complicated.
What is the role of the wall plate in a timber frame wall?
Note: In timber-framed walls, the wall plate has to span between the vertical timber studs and therefore has more of a structural role in distributing the roof loads in to the wall.
How does a tension strap work on a roof?
The guidance requires wind uplift forces on the roof to be resisted by a tension strap detail which holds the wall plate down by connecting it to the wall. The strap is typically a length of galvanised steel with a short crank at one end. It has holes along its length for fixing. The short leg is nailed to the top of the wall plate and a minimum of four fixings are required along the long leg to fix it to the wall. The straps are installed at a maximum of 2m centres along the length of the wall plate.
How thick is a wall plate in Scotland?
Quite why a 25mm thick wall plate is acceptable in some parts of Scotland but not elsewhere remains a mystery. NHBC Standards 2020 (which are applicable to the UK) is roughly similar in stating that wall plates should be ‘38x100mm or in accordance with local practice.’.
What is lateral restraint?
Lateral restraint is a separate matter whereby the roof structure acts to resist horizontal wind loads or other horizontal forces applied to the wall. The tension strap detail is ineffective in providing the lateral restraint but it can be achieved by fixing the wall plate to the wall with frame fixings, as described above.
Why do you need a long wall plate?
The requirement for relatively long lengths of wall plate is probably to aid line and levelling and to minimise the number of clashes between wall plate joints and rafter locations. When clashes do occur, the lap joint detail allows the rafters to be fixed as normal.
What is the most common form of building construction in the UK?
The most common form of building construction in the UK comprises a timber pitched roof supported by masonry walls. A timber wall plate is installed at the top of the masonry wall and the roof structure is fixed to it.
Where do wall plates sit?
For centuries wall plates have sat on the top of walls with little fixing down. They may have been bedded in cement but they and the roofs that were sat on them stayed there by there own weight.
Is a roof a wall plate?
If the roof is sat on framed construction then the term wall-plate is not used. Usually the top plates of the wall frame are beefed up and bolted connections from the roof are used via angle brackets.
Why are wall plates and roof structures bedded and fixed?
Wall plates and the roof structure shall be bedded and fixed to distribute and transmit loads, and to prevent uplift.
How to install a wall plate?
Wall plates should be: 1 bedded to line and level 2 fixed using nails or straps 3 a minimum of 3m or extend over at least three joists, rafters or trusses 4 joined using half-lapped joints, including at corners 5 38 x 100mm or in accordance with local practice.
Why do you need to bedded and fixed a wall plate?
Wall plates and the roof structure shall be bedded and fixed to distribute and transmit loads, and to prevent uplift. Trussed rafter roofs and traditional cut roofs should be supported on timber wall plates.
What is a hip rafter?
Definition of Hip Rafter: a rafter that runs diagonally between the roof ridge and the top of the wall plate, forming a hipped roof.
What is Valley Rafter?
Definition of Valley Rafter or cripple jack rafter: a rafter extending from the roof ridge down to the top plate of a wall at the intersection of a gable extension roof that itself abuts or intersects with the main roof.
What is a rafter run?
Definition of rafter run: the horizontal or level distance covered by the rafter - the bottom chord or base of a right triangle. In our sketch above the rafter run is shown as RUN under the left half of the roof.
What is a cripple jack rafter?
Definition of Cripple Jack Rafter or Valley Jack Rafter: a rafter running at right angles (90°) from the ridge of a roof down to the valley below. Cripple jack rafters or valley jack rafters never make it to a wall top plate - instead they intersect a valley formed by another roof.
How many ocs are required for rafter ties?
Building codes such as the ICC's 2012 International Building Code section 2308.10, Roof and Ceiling Framing typically specify that where rafter ties are used, they are required at intervals ranging from 12" to 24" o.c. depending on the roof design and the roof rafter spacing. Where rafter ties are not being installed with every rafter pair, model codes often specify that
What are horizontal ties?
Depending on its location along the roof rafter span or run, a horizontal tie or reinforcement may enjoy different names and suffers different forces. We detail these below: 1 Definition of Collar ties: High horizontal ties in the upper third of the roof - under compression 2 Definition of Mid-Span rafter ties: located horizontally in the middle of the rafter's run or horizontal span - neutral & varying 3 Definition of Low rafter ties: located in the bottom third or at the bottom of the rafter's run or horizontal span - under tension
Why does my roof truss sag?
It is because the bottom chord of a roof truss is in tension that the truss member can be as small as a 2x4. However the weight of a ceiling affixed to rafter ties of any dimension can cause ceiling sagging unless the lumber is also sized to support the vertical load or weight of the ceiling.
