timber-frame-specification

Timber Frame Specification

Frame Component Specification. Frame Walls, Floor, Roof.

This specification represents a standard timber frame service for developers where we manufacture and erect just the building frame.

Oversite Floor Construction

  • DPC – 225mm wide 500 mm visqueen embossed polythene.
  • Sole Plate – 2No. 38 x 89/140mm stress graded CLS supplied in random lengths for site fixing.
  • Fixings – Sole plates fixed using hamma drive screws or similar at centres dictated by our engineer.

Wall Panels

  • External Wall Panels – (Treated) 38x140mm.
  • Prefabricated Panels – 38x140mm C16 CLS kiln dried, factory fabricated, timber framing with timber studs secured at 600mm maximum centres.
  • External Boarding – 9mm OSB (Orientated Strand Board) nail fixed to the timber studwork.
  • Breather Membrane – Proprietary BBA approved breather membrane factory fixed to external sheathing by stainless steel staples fixed through white polystrap tape to distinguish wall tie positions.
  • Timber Beams/ Lintels – Structural beams/ lintels factory fixed for the timber superstructure only as dictated by Structural Engineer’s recommendations.
  • Head Plate – 38x140mm C16 CLS kiln dried timber supplied in loose lengths for site fixing.
  • Window/ Door Closers – 38x89mm timber closer to window cill.

Party Wall Panels

  • Prefabricated Panels – 38x89mm C16 CLS kiln dried, factory fabricated, timber framing with timber studs secured at 600mm maximum centres.
  • Racking (If required) – 9mm OSB (Orientated Strand Board) nail fixed to the timber studwork on the cavity face where dictated by Engineer’s recommendations to provide relevant racking.
  • Head Plate – 38x89mm C16 CLS kiln dried timber supplied in loose lengths for site fixing.

Internal Load Bearing  Wall Panels

  • Prefabricated Panels – 38x89mm C16 CLS kiln dried, factory fabricated, timber framing with timber studs secured at 600mm maximum centres.
  • Sheathing (If required) – 9mm OSB (Orientated Strand Board) nail fixed to the timber studwork on the cavity face where dictated by Engineer’s recommendations to provide relevant racking.
  • Timber Beams/ Lintels – Structural beams/ lintels factory fixed for the timber superstructure only as dictated by Structural Engineer’s recommendations
  • Head Plate – 38x89mm C16 CLS kiln dried timber supplied in loose lengths for site fixing

Internal Non Load Bearing Wall Panels

  • Prefabricated Panels – 38x89mm C16 CLS kiln dried, factory fabricated, timber framing with timber studs secured at 600mm maximum centres.

Upper Floor Construction

  • Floor Joists – Engineered joist cross cut to length; bundled into unit sets and delivered for site fabrication at 600mm centres maximum.
  • Header Joists – Single engineered joists or timber strand board  cross cut to length; bundled into unit’s sets and delivered for site fabrication.
  • Header Beams – 2No engineered joists or timber strand board cross cut to length; bundled into unit sets and delivered for site fabrication.
  • Perimeter Blockings – Stress graded timber blockings where required structurally.
  • Partition Junction – 38x89mm sawn softwood supplied in random lengths.
  • Noggins – for site fixing between joists running parallel to timber joists.
  • Decking – 22mm V313 (P5) chipboard or similar nail fixed to the timber joists on site to form floor diaphragm.
  • Adhesives – Proprietary resins and adhesives to secure decking.
  • Waistband Paper – 300mm wide proprietary BBA approved breather membrane supplied loose for site fixing over ring beam zone to maintain external envelope integrity.

Roof Structure

  • Trusses – Pitched Prefabricated timber roof trusses site fixed at 600mm maximum centres, designed and manufactured in accordance with BS5268 part 3.
  • Wind Bracing – Ex25x100mm sawn softwood supplied in loose lengths for site fixing in accordance with BS5268 part 3 and roof designers recommendations,
  • Loose Rafters – Ex50mm C24 graded sawn softwood supplied in loose lengths for site fixing.
  • Gable Ladders – 38x89mm C16 CLS framing with noggins fixed at 600mm centres maximum.

Structural Timber

All structural timber members are stress graded, regularised and kiln dried to contain an average moisture content of not more than 20% at the time of delivery. Preservative treatment is to conform to current Building Regulations and NHBC recommendations using a vacuum impregnation treatment process to repel fungal and insect damage. Floor joists, roof trusses/ timbers and internal non-load bearing partitions do not require treating.

Ancillary Components

  • Fixings
  • Timber Frame  – All obligatory nails, screws and/ or bolts for assembling

Superstructure – Exclusions

  • Ground floor construction
  • Oversite flooring build up
  • Damp proof membranes and gas membranes
  • Packing of sole plate materials in excess of +/- 5mm
  • Holding down straps
  • Stone or Finish Wall construction
  • Stainless steel brickwork wall ties.
  • Steelwork
  • No Steelwork has been allowed for.
  • Roofing
  • No soffit and facia

Miscellaneous – Exclusions

  • Any steelwork and supports to form balconies and terraces
  • Notching, drilling and framing for flues
  • Notching or drilling of service holes

Site Erection General – Inclusions.

1.    Examination of all foundations/ oversites for line, level and square to guarantee compliance with our minimum tolerances of +/- 5mm as dictated within the TRADA Technology Timber Frame Construction Handbook. Tolerances that surpass stated requirements will necessitate packing to level, at the customers cost, to a maximum of +/- 10mm. Any packing that surpass the TRADA requirements will require ‘hard packing’, by the customer, using a proprietary resin based mortar. A Structural Engineer must endorse any packing in excess of +/- 5mm stated by TRADA.
2.    All necessary labour for the erection element of the timber frame superstructure in one continuous visit. No provision has been made for return visits.
3.    Sufficient management of the labour only team and attendance to the customer by our visiting Contract Management team and Office based staff as necessary.
4.    The following fundamentals must be made accessible to, no less than 4 working days prior to commencement on site:
a)    Completed foundations/ over-site
b)    Vehicle and Plant Access
c)    Scaffolding (including necessary scaffolding certification)
d)    Hard Standings
All prices and programmes have been generated on the basis of a normal working week (Monday to Friday); working between the hours of 8.00 a.m. and 5.00 p.m. Weekend working may be arranged with the customer.
Adjustments to the stipulated working hours may have both a financial and timescale impact.

Site Erection General – Exclusions

1.    All scaffolding, which is required to meet the HSE legislative requirements.
2.    110V power supply and leads.
3.    Task, flood or Health and Safety lighting.
4.    Notching, drilling and routering for service runs and flues.
5.    Messing/ welfare and canteen facilities.
6.    Parking facilities for site operatives.
7.    Site office.
8.    Skips or similar provision for the removal of discarded materials from site, we will be responsible for tidying up our waste materials during our site duration and also the position of such waste material to a locally suitable point or skip.
9.    Security of our works outside working hours.
10.    Protection of our works outside working hours.
11.    Any road sweeping, wheel washing or cleaning requirements.
12.    Payment of any site fees or part of any aggregated costs levied by the customer, his agents or others.
13.    Hire costs of any tools or plant.

Frame Component Specification: Walls, Floors, and Roofs - A Comprehensive Guide

Timber frame construction is an efficient and cost-effective method for building residential and commercial properties. This article outlines a standard timber frame service for developers, focusing on the manufacture and erection of the building frame components, including walls, floors, and roofs.

Section 1: Oversight Floor Construction

The oversight floor construction includes the following components:
1Damp Proof Course (DPC): 225mm wide 500mm visqueen embossed polythene.
2Sole Plate: 2No. 38 x 89/140mm stress-graded CLS supplied in random lengths for site fixing.
3Fixings: Sole plates fixed using hammer drive screws or similar at centres dictated by our engineer.

Section 2: Wall Panels

Wall panels are divided into external, party, internal load-bearing, and internal non-load-bearing panels.
1External Wall Panels: Treated 38x140mm, prefabricated panels with 9mm OSB external boarding and BBA-approved breather membrane.
2Party Wall Panels: 38x89mm prefabricated panels with optional racking if required.
3Internal Load Bearing Wall Panels: 38x89mm prefabricated panels with optional sheathing if required.
4Internal Non-Load Bearing Wall Panels: 38x89mm prefabricated panels.

Section 3: Upper Floor Construction

The upper floor construction consists of:
1Floor Joists: Engineered joists cut to length and bundled into unit sets for site fabrication.
2Header Joists: Single engineered joists or timber strand board cut to length and bundled into unit sets for site fabrication.
3Header Beams: 2No engineered joists or timber strand board cut to length and bundled into unit sets for site fabrication.
4Perimeter Blockings: Stress graded timber blockings where required structurally.
5Partition Junction: 38x89mm sawn softwood supplied in random lengths.
6Noggins: for site fixing between joists running parallel to timber joists.
7Decking: 22mm V313 (P5) chipboard or similar nail fixed to the timber joists on site to form floor diaphragm.
8Adhesives: Proprietary resins and adhesives to secure decking.
9Waistband Paper: 300mm wide proprietary BBA approved breather membrane supplied loose for site fixing over ring beam zone to maintain external envelope integrity.

Section 4: Roof Structure

The roof structure includes:
1Trusses: Pitched prefabricated timber roof trusses fixed at 600mm maximum centres.
2Wind Bracing: Ex25x100mm sawn softwood supplied in loose lengths for site fixing.
3Loose Rafters: Ex50mm C24 graded sawn softwood supplied in loose lengths for site fixing.
4Gable Ladders: 38x89mm C16 CLS framing with noggins fixed at 600mm centres maximum.

Section 5: Structural Timber

All structural timber members are stress graded, regularised, and kiln-dried, with preservative treatment conforming to current Building Regulations and NHBC recommendations.

Section 6: Ancillary Components

Fixings for the timber frame superstructure are included, such as nails, screws, and/or bolts.

Section 7: Site Erection General

Inclusions for site erection consist of:
1Examination of all foundations/oversights for line, level, and square.
2All necessary labor for the erection element of the timber frame superstructure in one continuous visit.
3Sufficient management of the labor-only team and