RonaScreed FastDry Prompt

RonaScreed FastDry Prompt extended informationConsumption Rate:Mix 1Mix 2Mix 3Required per m2 @ 50mm0.5 litres0.5 litres1 litreRequired per m2 @ 75mm0.75 litres0.75 litres1.5 litresRequired per m2 @ 100mm1 litre1 litre2 litresRequired per m310 litres10 litres20 litresDrying TimeMix Designs 1 & 250mm75mm100mmTime to achieve 80% RH5 days6 days7 daysTime to achieve 75% RH8 days9 days10 daysMix Design 350mm75mm100mmTime to achieve 80% RH3 days2 days2 daysTime to achieve 75% RH4 days6 days6 daysThe data is based on drying @ 20°C and 60±5% relative humidity. Low temperature, high humidity, increased screed thickness and changing the mix design will delay drying. If the screed is covered with a curing membrane such as polythene, then the drying time starts when the membrane is removed. The relative humidity (RH) at the surface of the screed should be measured with a hygrometer, as required by BS 8203 Annex B, before proceeding to lay floor coverings. Standard practices should be followed. Drying time on site will vary according to site conditions. Increased screed thickness, lower temperature and higher humidity will lengthen the drying period; increasing the aggregate/ cement ratio will also increase drying time. Dehumidifiers should not be introduced until the screed has gained sufficient strength and lost sufficient moisture to reduce the risk of cracking and a 75mm thickness of screed should be allowed to dry naturally for 6-14 days approximately, depending on temperatureCompressive Strength1 day … 23N/mm228 days … 48N/mm2The above are typical laboratory results @ 20°C. Site strengths will be lower.Use of DehumidifiersScreeds should be sufficiently dry and strong before forced drying commences, at a temperature of 200C and air humidity of 60-65%, RonaScreed FastDry Prompt dries to 80% RH after 5-7 days of air curing between 50mm and 100mm thickness, and will gain a high proportion of its ultimate strength after the same eriod of curing. Forced drying should be delayed at lower temperature and when air humidity is high.Commissioning of Underfloor Heating SystemsScreeds should be sufficiently dry and strong before commissioning of underfloor heating commences, at a temperature of 200C and air humidity of 60-65%, RonaScreed FastDry Prompt Mixes 1 and 2 dry to 80% RH after 6-7 days and Mix 3 dries to 80% RH after 2 days of air curing between 75mm and 100mm thickness, and will gain a high proportion of its ultimate strength after the same period of curing. At this stage, underfloor heating may be turned on and the temperature may be gradually increased in accordance with the instructions of the heating manufacturer. Commissioning should be delayed at lower temperature and when air humidity is high, but it should still be possible to use the heating system to reduce drying time at lower temperature, which may be important in thicker sections of screed.Mix DesignsMix DesignsMix 1Mix 2Mix 3UseMedium to heavy dutyHeavy dutyMedium to heavy dutyPortland cement (CEM II 42.5)50kg50kg50kg0/4mm screeding sand150kg75kg150kg5/10mm granite-75kg-RonaScreed FastDry Prompt1 litre1 litre2 litresWaterTypically up to 8 litresTypically up to 8 litresTypically up to 8 litresYield per mix0.1m30.1m30.1m3Separation from drying concreteDrying concrete must be separated from the screed by polythene or RonaScreed DPM surface damp proof membrane. Screeds thicker than those referred to will take longer to dry out. Screeds which are wetted during or after their application or curing will take longer to dry out. Note that RonaScreed FastDry Prompt screeds are designed to be covered with carpet, vinyl, tiles or other coverings and are not designed as wearing screeds or toppings. For wearing screeds an appropriate Ronafix Mix Design or RonaScreed Self Smoothing Topping should be used.Areas of UseRonaScreed FastDry Prompt screeds can be laid in the following situations:bonded to concrete slabsbonded to existing screedsunbonded on slip membrane (minimum thickness 50mm)bonded to suitable bonded damp proof membrane such as RonaScreed DPM (minimum 25mm thickness)floating on insulating board or acoustic layer (minimum thickness 65mm residential only, all others 75mm)Bonded, Unbonded and Floating ScreedsRonaScreed FastDry Prompt screeds can be laid either bonded, unbonded or floating, determined by the substrate type. Bonded screeds must be laid on to a suitably prepared substrate (see Surface Preparation). Unbonded screeds are those laid on a slip membrane. Floating screeds are those laid on to an insulation board or acoustic layer.Bonded Screed (from 25mm)suitable substrate, mechanically prepared prime with Ronacrete Standard PrimerBonded Screed (from 50mm)suitable substrate, mechanically preparedprimer with cement : water (2:1)Unbonded Screed (from 50mm)solid substrate on 500 gauge polythene or other suitable slip membraneFloating Screed (65mm minimum)Light residential use onlyinsulation board or acoustic layerFloating Screed (75mm minimum)All uses other than light residentialinsulation board or acoustic layerDamp Proof MembraneA damp proof membrane should be present the under the concrete slab to prevent moisture penetration from below. If no membrane is present or if the concrete is drying, apply two coats of RonaScreed DPM or install a sheet or similar membrane. If RonaScreed DPM is laid on to a clean, sound and correctly prepared substrate as specified in the RonaScreed DPM data sheet it is possible to lay RonaScreed FastDry Prompt at a minimum thickness of 25mm, bonded to the RonaScreed DPM with a primer of Ronafix and cement.Mix Components & DesignThe basic components of a RonaScreed FastDry Prompt screed are Portland cement (CEM II 42.5), 0/4mm screeding sand, RonaScreed FastDry Prompt and sufficient clean water, failure to add sufficient water will not fully hydrate the cement and the screed will be more difficult to compact, especially when the screed is laid floating. Larger sized aggregates are used for concrete or granolithic finishes; see Table 4 of BS882.RonaScreed FastDry Prompt Mix 1 yields approximately 0.1m3. The density of the cured screed is approximately 2000-2100kg/m3RonaScreed FastDry Prompt Instructions for UseSurface PreparationThe surface on to which a RonaScreed FastDry Prompt screed is to be bonded must be clean, structurally sound and stable. All grease, oil, laitance and loose material must be removed. The surface must be keyed to expose the aggregate and to provide good adhesion. This is best achieved by scabbling, planing or shot blasting. The prepared surface must be cleaned (ideally by vacuum), damped with clean water and excess water removed.MixingRonaScreed FastDry Prompt must be mixed using a forced action mixer. Dry mix the cement and sand then add the RonaScreed FastDry Prompt liquid followed by sufficient clean water to produce a workable mix and fully hydrate the cement. The screeder should be able to make a ball of the mixed mortar and pull it apart without crumbling of the mortar.PrimingThe prepared surface must be thoroughly damped with clean water and the water allowed to soak in.Excess water must be removed and the appropriate bond coat applied. For screeds up to 50mm thickness a mix of 1:1 Ronafix: Portland cement brushed in to the surface or, over 50mm thickness, a 2:1 cement/water slurry. Before this dries the screed must be laid. If the bonding coat dries it must be vigorously scratched and reapplied.LayingStandard screeding practices should be followed. The mortar must be placed as soon as possible after mixing and well consolidated. Conventional tools such as float and trowel are used to obtain the desired surface finish.Embedded Conduits and PipesWhen laying conduits or pipes within RonaScreed FastDry Prompt screeds the conduit or pipe should be a minimum of 25mm beneath the top surface. It is advisable to incorporate reinforcing mesh centrally within the depth of the screed over the conduit or pipe, extending for not less than 150mm each side to minimise the risk of cracking.JointsBay proportions should not exceed 3:2 length to width, joints should be positioned as follows:construction joints in the substrate must be expressed through into the screedmovement joints in the substrate must be expressed through into the screedwhen laying on suspended floors, movement joints should be installed in the screed over support positions to accommodate movementisolation joints should be installed around the perimeter of the floor and around columns, manholes and fixed spaces to accommodate movementheated screeds may require movement joints positioned to limit screed bays to a maximum of 40m2 with a maximum bay length of 8m. This applies when rigid floorings and some types of resilient flooring are to be appliedseparate heating zones should be divided by expansion jointsCuringCuring must commence as soon as possible after finishing the screed. Cure the screed with tight fitting polythene, placed on to the screed as early as possible without damaging the surface. Cover for 24 hours then remove and air cure.PumpingRonaScreed FastDry Prompt modified screeds can be pumped to the point of laying. Tests have been conducted using Putzmeister equipment and specific guidance should be sought from Ronacrete Ltd.ContractorsUnlike other screeds of a similar nature RonaScreed FastDry Prompt can be purchased and applied by competent screeding contractors throughout the country. Ronacrete Ltd maintains a list of national and local contractors who are familiar with this type of flooring system and their application procedure. The use of RonaScreed FastDry Prompt is simple and straightforward and satisfactory performance will be achieved provided the correct methods are followed. There are obvious advantages in selecting a contractor who hasprevious experience of the material but if requested the Ronacrete Technical Department will provide guidance and assistance to other contractors.Other Flooring MaterialsDepending on the specific requirements of the floor system being laid Ronacrete may recommend an alternative product which may be more suited to the application. To discuss the use of Ronacrete materials for any application please contact the Ronacrete Technical Department for full technical and practical guidance at design and specification stage together with site assistance and practical backup.RonaScreed FastDry Prompt PackagingRonaScreed FastDry Prompt is supplied in 20, 210 and 1000 litre units.  Categories: All Products, Building Supplies Pallet Deals, Screed Pallet Deals & Bulk Buy