Uvas pasas

GENERAL

Cross-reference

General: Read with A90 General technical requirements.

PRODUCTS

Cover strips to joints in rigid board substrates

Bitumen membrane: To BS 747, type 5U.

Overlay to metal deck

Plywood: To BS EN 636 section 7 (plywood for use in humid conditions).

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Quality: Naturally durable timber, free from preservatives. Oriented strand board: To BS EN 300, type OSB/3.

Precast concrete paving slabs

Standard: To BS EN 1339, hydraulically pressed.

Timber trims, etc

Quality: Planed. Free from wane, pitch pockets, decay and insect attack except ambrosia beetle damage. Moisture content at time of covering: 22% (maximum).

Warm deck roof insulation generally

Expanded polystyrene board (EPS): To BS EN 13163. Extruded polystyrene board (XPS): To BS EN 13164.

Mineral wool (MW) roofing grade insulation board: To BS EN 13162. Phenolic foam (PF) board: To BS EN 13166.

Rigid polyisocyanurate foam (PIR) roofboard: To BS 4841-3. Rigid polyurethane foam (PUR) roofboard: To BS EN 13165.

Inverted roof insulation

Extruded polystyrene board (XPS): To BS EN 13164.

EXECUTION

Adverse weather

General: Do not lay membrane at temperatures below 5°C or in wet or damp conditions unless effective temporary cover is provided over working area.

Unfinished areas of roof: Keep dry and protect edges of laid membrane from wind action.

Incomplete work

End of working day: Provide temporary seal to prevent water infiltration.

On resumption of work: Cut away tail of membrane from completed area and remove from roof.

Applying primers

General: Use primer where recommended by membrane manufacturer. Surface coverage: Even and full.

Coats: Fully bonded. Allow volatiles to dry off thoroughly between coats.

Substrates

Surfaces to be covered: Secure, clean, dry, smooth, free from frost, contaminants, voids and protrusions.

Preliminary work: Complete, including grading to correct falls and formation of upstands, kerbs, box gutters, sumps, grooves, chases, expansion joints and fixing of battens, fillets, anchoring plugs/ strips, etc.

Moisture content and stability of substrate: Must not impair integrity of roof.

Renewing existing coverings

Substrate: Do not damage.

Timing: Only remove sufficient coverings as will be renewed and waterproofed on same day.

Laying metal deck overlay

Setting out: Lay boards with staggered joints and long edges at right angles to troughs in deck.

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Joints: Plywood overlays, allow 1 mm per metre panel size; OSB overlays, allow 2 mm per metre panel size.

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End joints: Centre over crown of deck. Fasteners:

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Type: As fastener manufacturer's recommendationsfor the purpose.

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Fastener heads: Flush with, or below board surface.

Laying vapour control layer

Laying: Flat and smooth.

Laying warm deck roof insulation

Setting out:

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End edges: Adequately supported.

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Joints: Butted together.

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End joints: Staggered.

Boards at completion: In good condition, well fitting and secure.

Mechanical fixing of waterproof membrane

Laying membrane: Loose, do not wrinkle or stretch. Installing fasteners:

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Use manufacturer's/ supplier's recommended methods and equipment.

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Insertion: Correct and consistent. Washers/ pressure plates/ bars:

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Distance from fixed edge (minimum): 10 mm.

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Fixing: Flush with membrane.

Sheet overlaps: Extend beyond washers/ pressure plates by: 50 mm (minimum). Surface condition at completion: Fully sealed, smooth, weatherproof and free draining.

Adhesive bonding of waterproof membrane

Laying membrane: Do not wrinkle or stretch.

Surface condition at completion: Fully sealed, smooth, weatherproof and free draining.

Welded jointing of waterproof membrane

Laying membrane: Loose, do not wrinkle or stretch. Side and end joints:

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Preparation: Clean and dry surfaces beyond full width of joint.

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Sealing: Weld together.

Surface condition at completion: Fully sealed, smooth, weatherproof and free draining. Adhesive jointing of waterproof membraneSide and end joints:

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Preparation: Prime, clean and dry surfaces beyond full width of joint and lap.

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Sealing: Apply continuous even coverage of adhesive to both surfaces. Mate and roll together. Do not wrinkle or stretch membrane.

Surface condition at completion: Fully sealed, smooth, weatherproof and free draining.

Tape jointing of waterproof membrane

Side and end joints:

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Preparation: Prime, clean and dry surfaces beyond full width of joint.

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Sealing: Apply self adhesive tape. Mate and roll together. Do not wrinkle or stretch membrane. Surface condition at completion: Fully sealed, smooth weatherproof and free draining.

Perimeter of membrane

General: Secure membrane at roof edge conditions, changes of plane, curb flashings, upstands to roof lights, etc. with mechanical fasteners.

Perimeter details

Thermoplastic membranes:

Upstands, edge trims, drips, kerbs, etc: Select method compatible with membrane, either:

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Secure preformed metal sections to roof structure with mechanical fasteners.

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Form flashings from waterproof membrane material.

Roof membrane: Select method compatible with membrane, either:

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Dress over perimeter profile. Overlap beyond fasteners to manufacturer's/ supplier's recommendations.

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Terminate in horizontal plane immediately adjacent to change in direction and secure with mechanical fasteners. Flashings: Dress over perimeter profile. Overlap horizontal roof membrane beyond perimeter securement to manufacturer's/ supplier's recommendations.

Sealing: Select method compatible with membrane, either:

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Weld together.

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Bond with adhesive and weld at overlap.

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Mechanically fix and weld at overlap. Elastomeric membranes:

Upstands, edge trims, drips, kerbs, etc: Preformed from waterproof membrane material. Reinforcing strip: Lay at edge of horizontal roof plane.

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Securing: Mechanically fasten.

Roof membrane: Dress over perimeter profiles.

Roof penetrations

Thermoplastic membranes:

Roof membrane: Cut around penetrations and secure to deck. Flanged sleeve:

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Installation: Dress over and around penetration.

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Roof membrane overlap to flange (minimum): 50 mm beyond fasteners.

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Protection to top edge of sleeve: Flashing or weathering cravat. Elastomeric membranes

Roof membrane: Cut around penetrations. Flanged sleeve:

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Installation: Dress over and around penetration.

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Seating: Flush to roof membrane.

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Roof membrane overlap to flange (minimum): 75 mm beyond fasteners.

Laying inverted roof insulation

Condition of substrate: Clean

Setting out: Loose lay with staggered joints.

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Cutting: Minimize.

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Small cut pieces: Avoid at perimeters and penetrations.

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Joints: Butt together.

Projections, upstands, rainwater outlets, etc.: Cut insulation cleanly to fit closely around. Completion:

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In good condition, well fitting and stable.

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Cover to prevent wind uplift and flotation as soon as practicable.

Laying stone ballast

Condition of substrate: Clean. Gravel guards: Fit to outlets.

Previously laid materials: Protect whilst laying ballast. Laying: Spread evenly. Do not pile to excessive heights.

Laying precast concrete paving slabs

Condition of substrate: Clean. Setting out: Minimize cutting. Joints: Open.

Completion: Slabs level and stable.

Inspection

Interim and final roof inspections: Submit reports.

Electronic roof integrity test

Testing authority: Approved independent testing body or the roofing contractor.

Timing of test: Before covering of membrane or prior to, and on completion of access by other trades. Condition of roof prior to testing:

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Waterproof membrane complete to a stage where integrity can be tested.

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Surface: Clean.

Test results and warranty: Submit on completion of testing.

Completion

Roof areas: Clean.

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Outlets: Clear.

Work necessary to provide a weathertight finish: Complete. Storage of materials on finished surface: Not permitted.

In document SEMINARIO DE GRADUACIÒN PARA OPTAR AL TÍTULO DE LICENCIADO EN QUÍMICA INDUSTRIAL. (página 61-0)