Wooden suspended floors

Transcription

1 UPONOR PEX PRODUCTION UNDERFLOOR HEATING WOODEN SUSPENDED FLOORS Wooden suspended floors

2 Uponor Underfloor Heating in Wooden suspended floors Wooden suspended floors The term suspended floors in this brochure refers to a floor construction mainly consisting of wood products where a load-bearing floor surface of wood, chipboard, etc. rests on wooden floor joists, either solid wood or I-beams with flanges of wood, board etc. The dimensions and recommendations are according to common use in the Nordic countries. Local standards and regulations must always be considered. How to heat a suspended floor Underfloor heating in timber joist floors generally requires more thorough planning than installations in concrete. In concrete screeded floors or wet installations, the screed spreads the heat and provides an even floor surface temperature. Wooden suspended floors do not conduct heat as efficiently. Heat diffusion plates are required in order to distribute the heat from the pipe to the floor surface. In order to prevent the surface temperature of the floor being uneven and to keep the supply water temperature at a reasonable level, the plates must have good contact with the floor surface, and as large a proportion of the floor as possible must be covered by plates. The loops are to be laid in sinuous pattern and the temperature drop in the loops at calculated temperatures should be no more than 5 C. The space between the floor joists should be insulated to limit downward heat loss through the void below the joists. In certain cases underfloor heating alone will not be adequate and some form of supplementary heating may be required. Where high heat flow density is required, the surface temperature to obtain the desired effect may be far too high. A floor surface temperature of up to 29 C is generally accepted, but materials used in suspended floor constructions may require lower temperatures. Thick floor materials with low heat conductivity will require high flow temperatures. Temperatures exceeding 60 C should be avoided. General information on wood materials and underfloor heating Wood is a hygroscopic material, so its dimensions fluctuate with variations in atmospheric humidity. When the humidity increases, moisture is absorbed and the wood swells. High moisture content may also have a negative effect on the adhesives used, e.g. in the manufacture of parquet flooring. At low atmospheric humidity the wood will shrink and cracks may appear between the boards. In order to reduce these fluctuations, relative humidity of 30-60% should be maintained in the room where the wooden floor is laid, both during and after installation. Types of wood that display substantial fluctuation (e.g. beech and hard maple) should be avoided unless they have been specially treated to reduce this. If the joists in a timber joist floor have a high moisture content from the start, the effective dehumidification that the underfloor heating brings about will mean dimensional changes in the joists. If underfloor heating has been installed, we therefore recommend that the floor joists be dried to a maximum moisture content of 10% before the floor is laid. Measurements are taken on the top side of the joists. In newly-built houses, the building materials normally contain a large amount of moisture. This moisture must be dried out as soon as the house has been insulated. Underfloor heating has been selected as the heating system, it must be taken into account that the process of drying out the joist floor is accelerated as soon as the underfloor heating is started up. It is necessary 2 Uponor Underfloor Heating Wooden suspended floors

3 for the underfloor heating to remain on during the drying-out process, even in summer. How to choose an installation method Uponor can offer several different solutions for installing underfloor heating in wooden floors. Choosing the most suitable system will depend on factors such as whether it is a new building or an installation in an existing floor, the distance between the joists and the final flooring covering material. Description of the various installation methods specifies the most important prerequisites for each system. It is generally a good idea to consult the structural engineer before choosing an installation method. If the floor is resting on I-beams, where cutting notches in the beams flanges is not normally permitted, it is particularly important that the installation be designed correctly from the beginning in consultation with the structural engineer and that any installation work be in line with his instructions. Room regulation An underfloor heating system should ideally be equipped with room thermostats and actuators to achieve maximum indoor comfort in each room or zone. Regulating the flow of warm water in the underfloor heating system can then optimise the room temperature. Overheating of the room may be caused by extra heat generated by sunlight, lighting, heat-generating equipment and human activity. Room thermostats maintain the desired room temperature in a particular room regardless of floor structure and floor type. To protect sensitive wooden flooring from being exposed to temperatures that are too high, it may be advisable to use a room thermostat with an external floor sensor that limits the maximum permitted temperature of the floor. A comfort controlling system will reduce the amount of wasted energy and provide environmental benefits. When comparing prices for the various alternatives, always compare the total installed cost, as the price of the individual materials for the underfloor heating installation does not generally provide a true picture. Uponor Underfloor Heating Wooden suspended floors 3

4 Uponor Heat Emission Plate 20 on floor joists This alternative can be used regardless of the joist spacing as long as the distance between the joists does not exceed 600mm. The floor surface will be raised and the pipe direction will be perpendicular to the floor joists. A B C D E F G A = Laminated parquet or laminated floor, min 7 mm B = Chipboard, 22 mm C = Possible vapour barrier D = Underfloor heating plate E = Underfloor heating pipes Wirsbo-pePEX, 20 x 2 mm F = Secondary spaced boarding (battens), 21 x 120 mm or 28 x 120 mm G = Floor joist Installation Nail or screw the battens (21 x 120 or 28 x 120 mm) using 2 nails (screws) for each joist. When nailing use galvanised fluted wire nails. The first batten should be nailed approx. 50 mm from the wall so that the heat emission plate can be positioned correctly. Leave half the distance between the last two joists free of battens, but nail a batten along the crossing wall to support the chipboard. Ensure that there is enough room left to allow for the positioning of the pipe coils. Lay the heat emission plates starting from the outer wall. Leave 300 mm by the cross wall to allow room for the turning loops. Cover as large an area as possible with plates (70-90%). The gap between the plates must be at least 10 mm but not more than 100 mm. The plates can be divided at the break notches to adapt the plate length to the room length. Any leftover plates from the first groove can be used as the first plate in the second groove to minimise wastage. The plates should be nailed firmly to the battens at one side so the groove for the pipe runs in a straight line. Position the pipes according to the layout pattern. Mark the routing of the pipes in order to prevent accidental perforation with screws. Lay vapour barrier as required. After pressure testing, the flooring material can be laid. Note! If the flooring is 15 mm laminated parquet (with-out chipboard), use 28 x 120 mm battens. The battens should finish above the last joist, 3 cm from the cross wall. The battens should not be nailed to the last joist until the coil has been laid. The parquet is laid on top, across the battens. Installation with battens finishing above the last joist 4 Uponor Underfloor Heating Wooden suspended floors

5 Uponor Heat Emission Plate 20 between floor joists This alternative can be used if the distance between the joists is 600 or 300 mm. If ceramic tiles are used as flooring, the joists must be at a maximum of 300 mm c/c. The floor surface will not be raised, and the pipe direction will be the same direction as the floor joists. A B C D E F G H A = Laminated parquet, 22 mm, or chipboard, 22 mm B = Possible vapour barrier C = Underfloor heating plate D = Underfloor heating pipes Wirsbo-pePEX, 20 x 2 mm E = Secondary spaced boarding (battens), 21 x 120 mm or 28 x 120 mm F = Cross bar, 45 x 45 mm with partition 600 mm G = Insulation H = Floor joist A B C D E F G H I J A = Tiles B = Sealing layer C = Flooring plaster 13 mm D = Flooring chipboard 22 mm E = Underfloor heating plate F = Underfloor heating pipes Wirsbo-pePEX, 20 x 2 mm G = Secondary spaced boarding, 21 x 95 mm H = Cross bar, 45 x 45 mm with c/c 600 mm I = Insulation J = Floor joist Installation Nail cross bars at intervals of 600 mm between the joists and nail or screw the battens to these. The top edge of the secondary spaced boarding should be on a level with the top edge of the joists. Leave an opening for the turning loops for the underfloor heating pipes. Make notches for the pipes where they cross the joists, next to the crossing wall. Always consult the structural engineer before this is done. Lay the heat emission plates. Cover as large an area as possible with plates (70-90%). The gap between the plates must be at least 10 mm but not more than 100 mm. The plates can be divided at the break notches to adapt the plate length to the room length. Any plating remaining from the first groove can be used as the first plate in the second groove to minimise wastage. The plates should be nailed firmly to the battens at one side so the groove for the pipe is in a straight line. Position the pipes according to the layout pattern. Mark the routing of the pipes in order to prevent accidental perforation with screws. Lay vapour barrier as required. After pressure testing, the flooring material can be laid. Uponor Underfloor Heating Wooden suspended floors 5

6 Uponor Cassette 20 between floor joists This alternative can be used when the distance between the joists is 600 mm. It can be combined with heat emission plates where the distance between the joists varies. The floor surface will not be raised and the pipes will be in the same direction as the joists. Uponor Cassettes are not recommended where tile flooring is laid. A B C D E A = Laminated parquet, 22 mm, or chipboard, 22 mm B = Possible vapour barrier C = Underfloor heating pipes Wirsbo-pePEX, 20 x 2 mm D = Underfloor heating cassette E = Floor joist Installation The cassettes should be laid out from wall to wall. Cassettes can be split so that the length is 385 or 770 mm. Cover as large an area as possible, leaving a gap between cassettes of at least 10 mm but not more than 100 mm. The distance between the wall and the first and last cassettes in each line must be at least 250 mm to allow room for the turning loops. After setting out and centring the cassette, nail one side to the joist. Then check, using a spirit level, that the cassette is level with the upper edge of the joists. Once the cassette is level, nail the other side. Make notches for the pipes where they cross the joists, next to the crossing wall. Always consult the structural engineer before this is done. The underfloor heating pipes should be laid in the cassette grooves according to the layout pattern. The central groove in the cassette is to allow for movement of the cassette in the event of temperature variations, and should not be used for the pipe. Lay vapour barrier as required. After pressure testing, the flooring material can be laid. Underfloor heating in underfloor heating cassettes for 20 mm pipes Note! The flooring should be nailed or screwed to the floor joists. Some parquet suppliers recommend laying a floating floor, but in this case a construction with battens and underfloor heating plates must be used. 6 Uponor Underfloor Heating Wooden suspended floors

7 Uponor Underfloor Heating Chipboard 17 This alternative can be used regardless of the joist spacing as long as the distance between the joists does not exceed 600mm. The board is designed to be used instead of floor boards or floor deck and the floor surface will be raised. The pipe direction will be perpendicular to the floor joists. For ceramic tiles, the joists must be at a maximum of 300 mm c/c. A lower water temperature than with the other alternatives can be used, as it is possible to use thinner floor coverings, and the turning plate with pre-glued aluminium plates will enlarge the active heated area. On the other hand, with the 17 mm pipe the flow rate and the pressure drop will be greater than in the 20 mm pipe. A B C D E F A = Laminated parquet, chipboard or laminated floor B = Possible vapour barrier C = Underfloor heating plate D = Underfloor heating pipes Wirsbo-pePEX, 17 x 2 mm E = Underfloor heating chipboard, 22 mm F = Floor joist Installation Lay out the panels crosswise to the direction of the joists. Begin by laying out the first turning plate at the furthest point from the underfloor heating manifold. Lay out underfloor heating chipboard panels in the first row. Adjust the length of the panels so that any joints between two panels are always exactly above a joist. Crosscut so that each panel spans at least two joist voids. If any panel only spans one void, it must be supported by an extra cross bar in the middle of the compartment. Begin the next and subsequent rows with a turning plate in the same way as the first row. The joint line between the turning plates and the first underfloor heating plate will be the same, but the underfloor heating plates are cut and laid in such a way that the joints on the floor surface will be offset. (fig) The chipboard panels should be carefully glued along the tongue and groove and against joists and cross bars. Glue and screw the panels to the joists. Countersink the screws at least 5 mm. Do not fill the countersink hole. Note! Do not glue chipboard/turning plates where the pipe passes beneath until the pipe has been installed. See also the section on making holes, page 8. Carefully clean the chipboard of all chips and debris. Push the heat emission plates down into the chipboard grooves. Cover as large an area as possible with plates. The gap between the plates must be at least 10 mm but not more than 100 mm. The plates can be divided at the break notches to adapt the plate length to the room length. Any plates leftover from the first groove can be used as the first plate in the second groove to minimise wastage. Position the pipes according to the layout pattern. Begin by connecting one end of the loop to the underfloor heating manifold, then draw the pipe to the beginning of the loop field. Use the holes in the turning plate for coming up from or dropping down into a joist floor compartment. Lay vapour barrier as required. After pressure testing, the flooring material can be laid. Uponor Underfloor Heating Wooden suspended floors 7

8 1 The turning plates must have support by the wall 2 Plates laid over a single compartment must be centrally supported from below by an extra cross bar 3 The plates should always be jointed on top of a joist and laid so that the joints are offset Mounting underfloor heating chipboard Mounting Heat Emission Plate Mounting pipe Uponor underfloor heating 17 is laid directly onto the floor joists and replaces the usual subfloor. 8 Uponor Underfloor Heating Wooden suspended floors

9 Assembly, making holes general information When installing underfloor heating in timber joist floors the work must be planned so that the loops do not obstruct subsequent work. Always begin by installing the underfloor heating manifold. Then decide which loop is to be connected to each outlet on the manifold and how the feeder lines to the various rooms are to be positioned. In order for pipes to pass crosswise to the direction of the joist holes must be made. This must always be done in consultation with the structural engineer. In cases where the underfloor heating is installed on top of the floor joists, ensure that the support for each batten and chipboard is not impaired. For installations using flooring chipboard that covers the entire floor area, it is particularly important for all crossing pipes to be in place before the flooring panels are fitted. In order to allow a feeder pipe to be laid under the chipboard, the gap between the panels and the wall must be at least 10 mm and the pa- nels closest to the wall must remain loose until installation is complete. The notch in the joists for the feeder pipe should be around 40 mm from the wall, with a maximum width of 50 mm. If space is required for several pipes, leave a support under the grooved section of the chipboard and make a new notch so that it ends up under the nongrooved section of the board. (see figure). 40 mm 20 mm 90 mm 130 mm Max 250 mm Uponor Underfloor Heating Wooden suspended floors 9

10 Flooring Before the floor surface is laid the underfloor heating installation must be pressure-tested, and the moisture content of the floor joists checked. Always follow the floor manufacturer s instructions with regard to maximum permitted floor temperature, vapour barrier, installation method, etc. Laminated parquet Laminated parquet Vapour barrier Flooring chipboard Underfloor heating plate Underfloor heating pipe If parquet is required, 7-15 mm laminated parquet can be laid directly on Uponor Underfloor Heating Chipboard 17. The boards should be laid floating across the pipes. Follow the parquet floor supplier s recommendations regarding possible gluing or whether the flooring is to be snapped together mm laminated parquet can be used directly on Uponor Heat Emission Plate 20 on floor joists if battens across the joists are 28 x 120 mm. The parquet is laid on top, across the battens. With cassettes or battens between the joists, 7-15 mm parquet is laid on 22 mm chipboard. 22 mm laminated parquet flooring can be laid across the joists with the cassettes or heating plates on battens between the joists. The boards should be nailed using galvanized fluted wire nails 60 x 23. In addition, the floor manufacturer s instructions must be followed regarding gluing of end joints, etc. Some parquet suppliers recommend laying a floating floor on the whole. As the flooring should be nailed or screwed to the joist if cassettes are used, a construction with battens and underfloor heating plates must be used in this case. Vinyl or wall-to-wall carpet Vinyl or wall-to-wall carpet Flooring chipboard Underfloor heating plate Underfloor heating pipe If the final surface material is to be vinyl, wall-to-wall carpet, etc, chipboard should be laid over the underfloor heating system as a bed for the covering. The chipboard should be laid across the underfloor heating pipes. Tongue and groove should be fully glued along the short and long sides. With Uponor Underfloor Heating Chipboard 17, chipboard has to be at least 10 mm. With 20 mm pipe options, 22 mm chipboard should be used, and the boards should be screwed to the joists at intervals of approximately 600 mm. 10 Uponor Underfloor Heating Wooden suspended floors

11 Uniform timber flooring Floorboard Vapour barrier Underfloor heating pipe Underfloor heating pipe Uniform timber flooring (floorboards) with a minimum thickness of 22 mm may be used without supporting chipboard with all 20 mm suspended floor options. With a heat demand of approx 50 W/m2, floor boards with a thickness up to 30 mm can be used without exceeding a water temperature of 60 C, giving a floor surface temperature of approximately 27ºC. The boards should be laid across the underfloor heating pipes and fastened to the joists as per the supplier s instructions. Uniform timber must be well dried out before fitting. Ceramic tiles Tiles Possible sealing layer Tile adhesive Flooring plaster Flooring chipboard Underfloor heating plate Underfloor heating pipe Following installation methods are used in Sweden, but for more detailed instructions, we recommend that the tile and plasterboard suppliers are consulted and that their instructions are followed. When tiles are to be used as flooring material, Uponor Underfloor Heating Chipboard 17 is recommended with a distance of 300 mm between the floor joists. Alternatively, Uponor Heat Emission Plates 20 can be used between floor joists at the same distance. The Uponor Cassette system should not be used with tiled floors. When laying ceramic tiles, flooring plasterboard should be fitted first on, perpendicular to, the underlying flooring chipboard. The plasterboard should be fully glued to the flooring chipboard. With the underfloor heating chipboard 17 the length of the plasterboard must be adjusted so that all joists can be screwed to the chipboard without damaging the pipe. Double plasterboards facilitate construction of slopes towards floor drains, but the water temperature has to be raised. Lay the flooring plasterboard with offset long and short edges. The two plasterboard layers should be glued together using a suitable adhesive. When installing ceramic coverings over underfloor heating, damage to the adhesive during setting should be avoided by not allowing any temperature fluctuations in the floor material during the first month after tile laying. If heating from the underfloor heating system will be required before and/or during the period tile laying is to be carried out, the floor material can be supplied with a maximum temperature of 20 C. The floor material must be kept at this temperature for at least 24 hours before and up to approximately one month after completion of tile laying. The heat of the floor can then be increased gradually by a maximum of 5 C per 24 hours until normal operating temperature is achieved. Altering the temperature too early or too quickly can reduce the strength of the adhesive and could thus shorten the useful life of the ceramic covering. Uponor Underfloor Heating Wooden suspended floors 11

12 Technical data 12 Suspended floor 17 mm fig T (K) Floor temp Floor cover 14 mm Chipboard Heat demand (W/m 2 ) Suspended floor 20 mm fig. 2 T (K) Floor temp Floor cover 22 mm Cassette 20/ Heat emission plate Heat demand (W/m 2 ) 12 Uponor Underfloor Heating Wooden suspended floors

13 10 8 Different flooring Wall to wall Parquette 7 mm fig. 3 T (K) 6 4 Tiles Plastic Heat demand (W/m 2 ) Maximum loop length Large rooms require more than one pipe loop in order to limit the dimensioning pressure drop of the installation. Long loops may also cause problems in maintaining an even floor surface, and big differences in loop lengths make it difficult to balance the system. In most installations, a pressure drop of up to 20 kpa in the underfloor heating pipes is acceptable. With a dimensioning water temperature drop of 5 C, the maximum loop lengths and the corresponding approximate heated floor areas in the table can be used as a guideline. Heat demand 17 mm pipe 20 mm pipe W/m 2 l, m area, m 2 l, m area, m Calculation of mean water temperature Fig 1 and 2 describe the difference in temperature between the temperature in the room and the mean water temperature in the pipe. Fig 3 shows how the required water temperature increases to maintain the heat output with other floor coverings. Example with Uponor Cassette (Fig 2): A room with a heat demand of 70 W/m 2 and an air temperature of 20 C needs a floor temperature of 26.5 C ( C). The temperature under 22 mm chipboard will be 39.3 C ( C) and the mean water temperature in a cassette installation will be 52.0 ( C). If a plastic carpet is used (Fig 3), an extra temperature drop of 0.7 C has to be added, resulting in a mean water temperature of 52.7 C. For a temperature drop in the loop of up to approx. 5 C, the flow temperature can be calculated as the mean temperature + half the temperature drop. With a temperature drop of 5 C the required flow temperature will be approx 55.2 C ( C). Uponor Underfloor Heating Wooden suspended floors 13

14 Material data Wirsbo-pePEX Underfloor Heating pipes Uponor Underfloor Heating uses Wirsbo-pePEX pipes, a cross-linked polyethylene (PEX) pipe with an oxygen diffusion barrier and the same excellent characteristics as other Wirsbo-PEX pipes. The oxygen diffusion barrier is glued to the Wirsbo-PEX pipe using a special adhesive polyethylene film and prevents oxygen leakage through the pipe walls causing oxidation of the carbon steel components in the system. The oxygen diffusion barrier in Wirsbo-pePEX pipes easily complies with the requirements of the applicable DIN standard (DIN 4726). A mechanical protective layer of PEX is applied to the outside of the diffusion barrier. Allow at c/c 200 mm (17x2.0) mm is approx. 6 m/m 2. Allow at c/c 300 mm (20x2.0) mm is approx. 4 m/m 2. Uponor Cassette 20 Uponor Cassettes measure 1150 x 530 (excluding fastening band) x 0.6 mm and are supplied with break notches for dividing into 380 and 770 mm long sections. Allow approx. 1.1 cassettes/m 2. Uponor Heat Emission Plate The Uponor Heat Emission Plate 17 measures 1150x190x0.5 mm and is supplied with two break notches for dividing into 190, 390 and 570 mm long sections. Allow approx. 4 plates/m 2 or 6 underfloor heating plates per underfloor heating chipboard panel 2400x600 or 4 underfloor heating plates per underfloor heating chipboard panel 1200x800. The Uponor Heat Emission Plate 20 measures 1150x280x0.6 mm and is supplied with two break notches for dividing into 190, 390 and 570 mm long sections. Allow approx. 2.5 plates/m 2. Uponor Chipboard 17 Uponor Underfloor Heating chipboard is chipboard with grooves for installation of Wirsbo-pePEX pipes 17x2.0 mm. The panels are available in two sizes, 2400x600x22 mm and 1200x800x22 mm. The grooves have a c/c distance of 200 mm. Panels are supplied without underfloor heating plates. Allow at 2400x600 approx. 0,6 chipboards/m 2 Allow at 1200x800 approx. 1,2 chipboards/m 2 Uponor Turning Plate 17 The turning plate is equipped with grooves for the underfloor heating pipes. Underfloor heating plates are pre-fitted (pre-glued) in the groove on the turning plate. The grooves have a c/c distance of 200 mm and match the grooves in the underfloor heating chipboard. The turning plate constitutes a load-bearing structure in areas where the underfloor heating chipboard cannot be laid. The dimensions of the turning plate are 600x400x22 mm. Allow 1-2 plates per 2 pipe lengths. 14 Uponor Underfloor Heating Wooden suspended floors

15 Uponor Underfloor Heating Wooden suspended floors 15

16 In keeping with our policy of continuous improvement and development, Uponor reserves the right to change specifications without prior notice. Uponor AB T +46 (0) Box 101 F +46 (0) SE Virsbo W Sweden