Despojo de tierras y territorios

Floor Joists

Floor to be constructed of kiln dried structural grade timber joists with sizes and spacing suitable for the proposed clear span as annotated on the drawing or in compliance with Tables below. Joists to be supported by heavy-duty proprietary galvanized metal restraint joist hangers built into walls or fixed to treated timber wall plates (same sizes as joists) resin bolted to walls at 600mm centers using approved 16mm diameter stainless steel fixings. Alternatively, joists can be built into walls using approved proprietary sealed joist caps. Joists are to be doubled up and bolted together for trimmers, under partitions and baths.

Floor void between joists to be insulated with a minimum thickness of 100 mm of 10Kg/m³

proprietary sound insulation quilt, ceiling to be a minimum 15mm plasterboard and skim and floor joist covering to be a minimum of 20mm softwood tongue and groove softwood boards or

moisture resistant particle/chipboard to give overall 30 minutes fire resistance. Floor joists to be provided with 1 row of 38 x ¾ depth solid strutting at ends between joist hangers or proprietary galvanized struts to BS EN 10327 fixed as manufacturers details, at mid span for 2.5 – 4.5m spans and 2 rows at 1/3 centers for spans over 4.5m.

Table 6: Spans for Common Domestic Floor Joist Sizes (Strength Class C24)

Supporting domestic floor loads & non load bearing timber stud partitions (imposed load not exceeding 1.5kN/mm2) Size of joist Breadth X Depth (mm) (mm) Spacing of joist (mm) 400 450 600 Maximum clear span (m)

47 97 47 120 47 145 47 170 47 195 47 220 75 220 2.12 2.01 1.75 2.70 2.59 2.34 3.25 3.13 2.84 3.81 3.66 3.32 4.36 4.19 3.81 4.84 4.70 4.29 5.41 5.26 4.91 Trimming/trimmer/trimmed joists

Trimming/trimmer/trimmed joists sizes to be in accordance with span tables below, for support of domestic floor loads & non load bearing timber stud partitions imposed load not exceeding 1.5kN/m2, or 1.4 kN at the center or end of joists, dead load of floor construction should not exceed 0.5kN/m2. Double joists should be mechanically fixed together using at least two bolted connections or at 1/3rd spacing, using 12mm diameter high tensile bolts & 3 x 50mm steel washers at each bolt end. Joists to be supported on heavy duty galvanized joist hangers to current British Standards and fixed in accordance with joist hanger manufacturers details. Notches / holes/cuts in structural timbers should be carried out in accordance with guidance details and BS 5268-2002.

Table 7: Spans for Common Trimmer Joist supporting Trimmed Joists (Strength Class C24)

Length of trimmed joists (m)

1.0 2.0 3.0 4.0 Size of trimmer (mm) Clear span of trimmer joist (m) supporting

trimmed joists 2 x 47 x 145 2 x 47 x 170 2 x 47 x 195 2.68 2.27 1.97 1.68 3.21 2.68 2.33 1.99 3.69 3.09 2.69 2.31

Table 8: Spans for Common Trimming Joist supporting Trimmer Joist

(Strength Class C24) Supporting domestic floor loads & non load bearing timber stud partitions (imposed load not exceeding 1.5kN/m2)

Length of trimmer joist (m)

1.0 2.0 3.0 max Size of trimming joist (mm) Clear span of trimming joist (m) supporting

trimmer joist 2 x 47 x 145 2 x 47 x 170 2 x 47 x 195 2 x 47 x 220 2 x 75 x 220 2.62 2.42 2.25 3.08 2.84 2.65 3.54 3.27 3.05 3.99 3.70 3.46 4.66 4.32 4.05

Diagram 15: Typical plan layout of opening formed in upper floor(s) using trimming, trimmer and trimmed joists. (not to scale) See guidance tables for joist sizes

Notches / holes/cuts in structural timbers

Notches / holes/cuts in structural timbers should be carried out in accordance with BS 5268- 22002 and should not be deeper than 0.125 times the depth of the joists and should be not closer to the support than 0.07 times the span and not further away than 0.25 times the span. Holes should have a diameter not greater than 0.25 times the depth of joist and should be drilled at the joist centre line. They should be not less than 3 diameters (centre to centre) apart and should be located between 0.25 and 0.4 times the span from the support. Notches or holes exceeding the above requirements or cut into other structural members should be checked by a structural engineer

VOID OR STAIR WELL

Double member trimming joist supporting trimmer joist - sizes as guidance table or can be a supporting wall Clear span Cle a r sp an Cle a r sp an

Double member trimmer joist supporting trimmed joists - sizes as guidance table

Trimmed joists- sizes as guidance table

Floor joists - sizes as guidance table Important note: strapping & strutting

of floor joists to be accordance with guidance details.

Sound insulation to floors within the dwelling

Intermediate floors to be provided with sound insulation as described in the relevant floor section in this document.

SVP pipe boxing

SVP pipe boxing to consist of soft wood framing, 2 layers of 15mm plasterboard and skim and void filled with mineral wall quilt for sound insulation and fire/smoke stopping. Boxing to be continuously carried up to roof space for soil and vent pipe and provided with air grills where an air admittance valve is used. Ensure all gaps & all voids are sealed to prevent any air leakage. Exposed intermediate upper floors

Semi exposed intermediate timber floors over unheated areas such as garages, porches, walkways, and canopy‘s to be insulated with the following minimum thickness and types of insulations to achieve a U-value 0.22w/m².k as in Table 6 below. Where the construction is open to the environment a vapour barrier and proprietary external mineral fiber or similar 30 minute fire and moisture resistant boarding is to be applied to the underside of the floor.

Diagram 16: Typical section through an upper floor (not to scale)

Table 9: Insulation requirements to exposed upper floors U-value no worse than 0.22 W/m².k

Insulation product K value Required thickness of insulation (mm)

Kingspan TF70 0.023 110 Celotex FR4000 0.022 110 Jablite Jabfloor Premium 70 0.030 130 Jablite Jabfloor 70 0.038 160 Rockwool Flexi 0.038 140

Double glazed window bedrooms/ inner rooms to be fitted with openings suitable for escape as detailed in guidance

100mm minimum width insulation block (see options in guidance)

Wall grade insulation (see options in guidance)

50mm clear cavity if using partial fill cavity wall insulation (see options guidance) Wall ties and spacings as detailed in guidance

100mm minimum width external wall in materials to match existing or as specified in planning permission

Weep holes over all lintels

Proprietary insulated steel lintels (with dpc trays and stop ends) suitable for clear spans and loadings in compliance with lintel manufactures standard tables

Galvanized steel straps at 2m ctrs built into cavity and fixed over 3 joists with noggins

Sound insulated stud partition

22mm t & g moisture resistant floor boarding Strutting between joist (see guidance for spacings)

Floor joists (see construction details and table in guidance for sizes of joists suitable for clear spans)

Sound insulation quilt as guidance

Sound insulated plaster board achieving 30 minutes fire resistance

100mm dense concrete partitions precast

concrete/proprieteray steel lintols, sizes suitable for clear spans as manufactures standard tables Floor joists doubled

up under partition walls & baths Damp proof course and insulated closer