Could I fit XPS in the rafter gaps after the roof is up to create a thermal break? Where double lapped purlins are used, the lap length should take up 15% of the span. However, it all comes down to the project requirements. I'm in Blacksburg VA if that helps. The purlins of a roof support the weight of the roof deck. Furthermore, if manua l analysis is employed to analyze a truss loaded in such manner, such secondary stresses cannot be captured since we normally assume pinned connections. Erythematics is the substance that transports water. A 3-ply roof can be . This standard measurement should give you the approximate number of purlins you need for your project. The benefits of a metal roof are worth giving metal roofing a chance. Which Are The Best Materials For Roof Purlin? The standard spacing for aluminum and galvanized roof purlins is 1.0 to 1.2 meters. So, you should support your purlins with rafters to prevent curving. Homeowners across the US report spending $11,700 or $727 per square, to install a standing seam metal roof on a 1,600 sq.ft. The zinc and chromate layer is thick and resistant to corrosion and able to protect the inner layer for a longer period. Draw a horizontal line with the precise measurements that allows roof purlins to fit. Usually we install standing seam roofs on 1x4 purlins or battens (some horizontal and some in 45 angle). The best purlin spacing for corrugated metal roofs is 18 to 24 inches. They are also good for supporting beams used in flooring and can be used as joists. Choosing the right underlayment for your roof can be a difficult decision. It depends on their factory size and technology they applied. Taking on different home projects is something Arthur Callahan is passionate about. However, having vapour barrier is also recommended as these barriers prevent water from accumulating in the walls and let the moisture have its proper place. In the case of double-span purlins, you may have a single purlin running the entire span (double unlapped) or two purlins overlapping over central support to provide continuity (double lapped). Moreover, it results in higher price because the products prices include more transportation costs and benefits. Read on to learn the different types of roofing purlins, what they do, and how to properly install and space your purlins for the highest impact. Bolting only in the web of lapped purlins does not provide full structural continuity and excessive loads could be placed on to roofing screws that penetrate both purlins within a lapped region. There is no definitive answer to this question as it depends on a number of factors, such as the specific type of galvanized roofing and treated lumber being used, the climate and weather conditions in the area where the roof will be installed, and the expertise and experience of the roofing contractor. Without a vapour barrier, metal roofs are installed over purlins. Z purlins are used to give a building its desired shape and roof structure. While actual tin roofs existed a while back, tin (the metal) is rarely used in roofing anymore. Due to the exceptional features of a vapour barrier, it is advisable to install them to better work with other equipment. Even if shakes or shingles are installed on spaced sheathing, the roof deck beneath the ice barrier should be solid sheathing. In particular, local or distortional buckling or lateral displacement can occur, in which portions of the compression flange, web or connectors can buckle or shift from their initial position. Is the phrase newest addition to the family grammatically correct. Traditionally, metal roofs have used standard 30-pound felt paper underlayment. Metal roofs do not appear to disrupt your phone signal any more than any other material. Do not leave gaps in this underlayment. However, prices may be lower or high due to importing fee charged for delivering the material right at your doorstep. Besides, the main problem with wood is it being dry when it goes up. Metal rib or corrugated roofing. Your inquiry will be replied in 24 hours. wind and snow load). if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[336,280],'homeeon_com-banner-1','ezslot_5',135,'0','0'])};__ez_fad_position('div-gpt-ad-homeeon_com-banner-1-0');The amount you decide to spend on purlins will be determined by the thickness and size of the purlins. Metal roofs installed on solid deck with underlayment can be installed on battens as well. A purlin is a horizontal bar that supports the weight of your roof decking and prevents it from being blown away by strong winds. Purlins are essential and beneficial components when roofing. It does not assure maximum protection unless further coating is applied to prevent rusting. The purpose of the underlayment is largely that it is required by code. I want to install a standing seam metal roof. Tables are given for 5 or more spans. Twenty-four inches is a common spacing of furring strips for a metal roof. Corrugated metal roofing, in addition to standing-seam roofing, is available in corrugated sheets. Different purlins are used for different purposes, including structural support of walls or floors. Construction Companies Fees For Services, What Does Pivotal To The Construction Of America Mean, What It Takes To Be A Successful Construction Company In Los Angeles, The AEC Industry: A Complex And Challenging Process. Thus, there are two prevalent types of roofs which are popular in the market and known for their unique features. You should consider closer purlin spacing for greater roof strength if youre building in a location prone to heavy snow loads or high winds. You should set and space purlins evenly to ensure they support the trusses. Consider Using Crossed Battens. The second thing to consider is the pitch of your roof. If the lower web hole in a lap is used for attaching fly bracing ensure that an additional bolt is used. Yes, underlayment should be in place. An open-cell foam (about 0.5-pound density) is the most cost-effective way to insulate, but any opening over 1/16" could cause the foam to expand out onto the roof. Still, you need to make sure that the gap is not more than 1/8 inch. Then several purlins run across the rafters, holding them together and providing the surface for roof sheeting. This will be a 29 gauge steel, typically made on site, and covered . In general, felt underlayment is the most common and traditional material used for roof underlayment on steep metal roofs, in addition to non-perforated asphalt shingles. Perhaps to choose the best, one should look at their budget. Which is grammatically correct tomorrows or tomorrows. Metal building purlins are much stronger than their wooden counterparts, affording builders more room for maneuver. Purlin could be made from plywood, metal sheeting or wooden panels. For many applications, a layer of plywood underneath your metal roofing is an unnecessary expense. The first is to apply an approved underlayment over the old shingles. Cut the corners sticking to the sides of the chimney at 45 degrees from the roof deck and wrap them around the chimney. Most types of metal roofing require the assistance of a skilled craftsman. Take a purlin and install it, beginning with its corner. If I use R19 it is 6 inches so there would be 2 inches of space between the insulation . Hot-formed steel is the best material for roof purlins because of its strength and competencies to support the roof. You need a gap on the roof so your room could breathe. Horizontal 14 purlins, 24 OC screwed through to rafters. Insert two more inches in the 16-inch spaces on the rafters since they are automatically positioned at intervals. Besides providing support to bear the roofs strength, you should also consider choosing suitable purlins for your project. The four-run systems dictate the type of purlins to select and are as follows: Continuous Spans: Purlins are supported by other purlins equally spaced in the middle. They will help you decide the purlin sizes and span according to your places weather condition. Youll almost certainly want to use one long 2-by-4 as you walk up the roof. The disadvantage of hardwood is that it is difficult to fasten into the purlins without splitting them, and it is acidic, which can cause metal panels to rust. Richard, the spacing of your battens / purlins needs to come from the panel manufacturer. Line up the blue lines of the underlayment. Purlin span is like the length of the purlin. I had to deal with the issue of metal coming into contact with pressure-treated wood for the second time. Corrugated panels range in width from 2 feet wide by 8 feet long to 12 feet long, with 2 12 inches corrugations on each side. In addition, welding will locally remove the protective coating, leading to a potential reduction in durability. In their design life, purlins are subjected to dead load (e.g self weight of sheeting materials and accessories), live load (e.g. Additionally, use struts to complement the purlins. It will make installation harder in my view. Put only two nails for now, at each end of the fold line. Most woods are also not resistant to pests. Overlap the next panel straight above the first by 12 . They must therefore be considered beyond the scope of this manual. They expand and contract reasonably in extreme temperature changes. Purlins are installed horizontally under metal roofs. In that case, do you have drywall on the ceiling yet? All rigging, scaffolding and safety equipment must comply with the relevant codes, Australian standards and statutory requirements. if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'homeeon_com-box-3','ezslot_2',132,'0','0'])};__ez_fad_position('div-gpt-ad-homeeon_com-box-3-0'); This article explores all the necessities of purlins that will come in handy when roofing. Make sure there's a 1-inch overlap the edge of the roof by one-inch then secure it by drilling 1-and-1/2-inch galvanized metal screws through the panel in 12-inch to 16-inch intervals. It may appear strange to attach metal roofing directly to your buildings roof structure without the use and expense of plywood, but it does. Red oxide purlins, also called printed purlins, are prominently used in roofing than galvanized types. Condensation beneath the ribs will flow down the fascia board behind the lock strip if the lock strip is put over the underlayment. Thanks. Purlins are already attached with a hundred screws so they are not coming off. On the other hand, many residential and commercial buildings have roof purlins spaced 1 to 2 feet apart.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[250,250],'homeeon_com-large-mobile-banner-1','ezslot_7',137,'0','0'])};__ez_fad_position('div-gpt-ad-homeeon_com-large-mobile-banner-1-0'); Ran a tape measure from one side of the rafter to another on the roof to get the number of purlins needed. Metals that have dissimilar electrolyte connections can corrode when a small amount of electricity passes through an electrolyte. Both inward and outward capacities are influenced by bridging in double spans. Underlay support Underlays must be supported either by polypropylene tape, or 0.9 mm minimum galvanised steel wire mesh. Make sure to lay a 1/4 inch gap between the two places. You can even overlap them during construction to build a more durable roofing frame. Building owners can extend the lifespan of their new roof and save the expense of a roof tear-off by having roof contractor Pasadena install metal roofing over existing shingles.. I plan on removing all of the old cedar shakes and felt. So, never confuse purlins for rafters. What is the correct sentence for Those houses are theirs? The spacing (on sloped roofs) also depends on the truss spacing, truss type, truss slope, and roof covering. You had better work with knowledgeable and dynamic staffs, which will push the process going much faster. Metal Roofing 101 - #DIY steel roofing installation over shinglesSubscribe: http://bit.ly/SubDeboss | Merch: https://debossgarage.com/merchWatch next, " How . Also, will we need anything else for a moisture barrier. As a roof expert, he provides helpful tips and information. There are several factors involved in answering that question. Underlayment plays an essential role under the roof. Install the purlins on the rafters with a strong underlayment material for maximum support. Communication: 24/7 hotline, 24/7 email, fax, website. Western States Metal Roofing has been providing contractors with materials for successful installations for more than two decades, despite the fact that we do not install ourselves. By tradition, purlins are arranged depending on the direction of the roofing slope. One less row of bridging can be used for internal spans if inwards capacity, the recommended minimum bridging and practical spacing requirements allow. If not, a vapor barrier behind it would be wise. Secondary framing components are known as girts and purlins, and they work like this: Girts provide additional support for walls: They work in conjunction with columns and wall panels to support vertical load, improving both strength and stability. A purlin is a horizontal bar that supports the weight of your roof decking and prevents it from being blown away by strong winds. Roof Hit is reader-supported. A variety of sizes of standing seam and batten sheets are available. If you live in an area with a lot of snow and ice, youll want to use a harder wood like oak or maple. The second way is to install 14 purlins over the shingles. Its use on residential projects is far less common, but has been done a lot, especially in rural areas. If they are not steelmakers and need other steel supplier, they cannot be sure about the exact material and production process. Other than reputation , there are some elements that make the best purlin supplier. Z purlins are the stronger of the two purlin types. Secondary framing comes in two configurations, CEE and ZED. In this situation, additional care would be needed in hole detailing. log in. What will happen if your purlin are rusty after 3 months being used and when you contact your supplier, they blame it for the steelmaker. Theres common confusion about tin as a roofing material. James advises when retrofitting over an existing standing seam roof determine if the existing roof system has stand-off clips with or without thermal blocks. Therefore, roofing using wood purlins is not advisable in wet areas. reduced end spans) each purlin should have 7.5% of each adjacent span added rather than 7.5% of that purlins span. This underlayment protects the decking or old shingles from any condensation . The standard purlin spacing for metal roofs is four to six feet. "If not, a standard retrofit sub-framing system will not allow a positive attachment to the existing roof purlins." Flashing, Seams and Sealants Underlayers will keep your house from being directly exposed to the elements if the roof covering or flashings blow off or penetrate the interior of the house. Wood pressure treated for outdoor construction, such as bridges and decks, is becoming increasingly popular. This underlay for metal roofing is the synthetic, woven, water-shedding underlayment, which has high performance. Min. Because they add mid-span support, purlins allow longer spans, enabling you to create a wider building. The cleat bolts go through the cleats and the wood/metal purlins. Purlins provide additional support for the roof: They create a horizontal diaphragm that supports the weight of your buildings roof deck whatever material you use for the roof itself. Zinc and paint in combination (synergistic effect) produce a corrosion protection approximately 2X the sum of the corrosion protection that each alone would provide. When using 29 gauge metal roofing, your purlins should be 1.2 meters apart when using 0.7mm roofing sheets and no more than one meter apart when using 0.5mm roofing sheets. It is also worth noting that because of its lower copper content, CA-C is a more user-friendly treatment material. Wood Purlin is good for use with the fibre cement sheeting. The other method is to install 1 x 4 purlins throughout the roof. Fasten the field area in the middle of the roll a minimum of 24 O.C. To have a metal roof over purlins and no vapour barrier is a good combination but not the best one. Its more affordable and easier to work with, but it also presents some structural stability issues that must be considered as part of your metal building framing options and overall design. In many instances considerable stress concentrations are likely to arise, even with good quality welding. How do I insulate and properly vent between the insulation and the underside of the plywood roof underlayment. The polythene or plastic that is used in the making of the synthetic roof underlayment makes it a market leader. This is the fastest way to install but it doesnt provide the flattest surface for metal roofing installation. Purlins on edge: Install the purlins on edge using one 60D galvanized ring shank nail for medium-spaced trusses. Steel is more durable and heavier than aluminum when it comes to metal roofing. Stay tuned to read till the end to learn some beneficial facts about the topic under discussion. Walls and rafters, in turn, support the purlins. To have a purlin installed below the meta roof is the most recommended option, as purlins increase the roof's life by lifting it. Who created the Whose House? The installation of Purlins can be hazardous and will require an adequate safety plan be in place prior to handling or installing of these products. The general standard for roof purlin spacing is one meter to 1.2 meters, with an industry average of 4 feet. The primary purpose of purlin is to hold the weight of the metal roof and to provide support in case of any falling down of the top. You'll note that this is slightly larger than the recommended spacing for 29 gauge metal roofs. Oriented Strand Board, commonly referred to as OSB, is a type of engineered lumber similar to particle board, formed by adding adhesives and then compressing layers of wood strands. Theyre shaped on a bending press, to create a web with two flanges. The third thing to consider is the weight of the metal roof. Secure the purlins and underlayment with 2 1/2 to 3 inch ring nails or decking . This post will be focusing on design of steel purlin using cold formed sections. However, its a good place to start when working on purlin spacing. This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic. Purlins are supported either by rafters or the walls of the building. Because hot-dip galvanized steel is resistant to harsh chemicals and corrosion, it is a suitable material for use in harsh environments. Purlin could be made from plywood, metal sheeting or wooden panels. Yes, you can use pressure treated wood under a metal roof. It is extremely versatile to use hot dip galvanized or triple zinc coated metals. I currently have cedar shakes over 1x4 purlins spaced every 12". Wood is also one of the purlin materials manufacturers use but is susceptible to insect attacks and rotting when exposed to moisture. When installing a metal roof over an existing roof, insulate the spaces between the wood strips with rigid insulation to prevent condensation before installing the roofing. It applies to both galvanized and red oxides for the 14 gauge types. Metal roofs are durable and long lasting, and can offer a high level of protection against the elements. For example, purlins should be placed eight feet from 24 struts and six feet away from 26 struts. Unfortunately, timber is heavy and prone to rotting. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. When made of wood, it is usually covered with some sort of weatherproofing and sometimes an insulation material. Single purlin span is the span that is simply supported by means of bolting the web of the purlin to a cleat or other rigid structure. Heavier metal roofs don't need as much support as lighter alternatives. It is non-pressure treated lumber that is installed on the roof in a specific pattern and screw pattern and is 1 x 4 x 12 feet in size. When you found gaps or channels between the insulation pieces, it is better to leave it that way so the air could get into the house. You should go for Z-section purlins if youre shopping strictly for roofing purlins. The wood purlin and sheeting combine well to ensure that the room below is breathable and can safely store whatever you need to be kept safe in the room, from livestock to grain or other organic materials. Red Oxide VS. Galvanized Purlins For Roofing. Consult your contractor or engineer to get the right purlins for the best results. The reason is that 26-gauge metal roofs are a lot heavier than their 29-gauge counterparts. Your risk is when warm moist air from inside hits the cool back side of the roof system. If you have a shallower roof, you can use a softer wood. Quality management system: ISO 9001:2008 International Standard. Additional stability or support can come not only from girts, purlins and eave struts but also from additional stiffeners. Sharkskin Ultra . Metal roofing panels rated for "architectural use" attached to purlins (horizontal pieces of wood or metal fastened to roofing trusses) are structurally sound when installed according to your roofing manufacturer's instructions and local building codes. The purlin spacing for 26-gauge metal roofing is 4.5 feet. The purpose and uses of Purlin and vapour barrier have been discussed in detail above. I live in Hawaii and want to re-roof. Does it matter if we place the wood slats 24 inches or 18 inches apart. In conclusion, purlins are essential in roofing. Purlin Laps Repeat the procedures to get the width of the roof. They add valuable support and improve building stability by distributing the weight of the roof decking. Purlins are critical when installing a metal roof. Lap lengths that are less than 10%, or 5% on any side of a support, may not be strong enough for the long-term integrity of the . Basically all metal roofs that can be installed on battens can also be installed on solid decking with underlayment. document.write( new Date().getFullYear() ); ferkeybuilders, How To Install Peel And Stick Roofing On A Metal Roof. Technology: seven technology steps, modern machinery and advanced technology are applied to save energy and reduce production costs. If you are considering using pressure treated purlins under a metal roof, there are a few things you should know. It has an adhesive backing with a peel and stick feature. There are two good reasons for installing roof sheathing and roofing underlayment under metal roofing: 1. 5. Foam. The first is to apply an approved underlayment over the old shingles. Last but not least, you have to choose the best supplier for you to order purlin. How Do You Install Metal Purlins On A Roof? If you do not have an Ask the Experts forum user account, Steel Purlin is a direct replacement for wood purlin. Snap chalk lines along each side of a valley, parallel to the valley and one inch from the valley at each side. As compared with thicker hot rolled shapes, they normally offer the advantages of lightness, high strength and stiffness, easy fabrication and installations, easy packaging and transportation etc. the new metal roof over synthetic underlayment or 30 lb. A.Paul Fisette responds: I would not recommend using pressure-treated purlins under steel roofing without taking special precautions. Double cleats are generally only used where successive purlins (usually unlapped) are butted together. metal roof, light yet so strong. I would not recommend using pressure-treated steel purlins under steel roofing unless special precautions had been taken. Generally, most roofers arrange purlins depending on the roof slope. Metal does not work well with pressure treated wood. If galvanized steel or stainless steel is used as a corrosion-resistant coating on treated lumber, it can be used on galvanized metal. However, being made from wood, purlins can rot. Legal DisclaimerHomeeon.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. In architecture, structural engineering or building, a purlin (or historically purline, purloyne, purling, perling) is a horizontal beam or bar used for structural support in buildings, most commonly in a roof. Normally, purlins are not designed to be walked on unless fully covered by correctly installed roofing materials or the correct grade of safety mesh. I don't have a problem with insulation or ventilation right now. The rule of thumb is to space your purlins closer (as close as under a foot apart) if you live in an area with heavy snow loads or high winds. This makes them an ideal choice for use in areas where the weather is harsh or where the roof is subject to leaks. Purlin is usually installed with a vapor barrier, or they can be installed with roof underlayments with synthetic underlayment or felt underlayment. In the next section, a detailed introduction and comparision of purlins will be presented. Metal roof installation requires specialized equipment, tools, training, and knowledge, making the final cost . You need at least two, one at each end, for a rectangular or square room, though many projects require several trusses to form the shape of the roof. The pressure treated wood will help to protect the roof from the elements and will also add an extra layer of insulation. Installation techniques can impact your new roof's performance. If metal parts come into contact with wood, it is recommended that they be galvanized or stainless steel. Laps must be bolted in the outer web hole (closest to the sheeting), and the inner flange holes provided. There are many different types of roof purlins based on material and styles. I am going to home Is this sentence correct? What I mean in this regard is that purlins should be placed at the nodes of trusses and not on the members themselves so as not to induce secondary bending and shear forces in the members of the truss. Therefore, a purlin should be adequately strong to withstand the loads it will encounter during its design life and should not sag in an obvious manner thereby giving the roof sheeting an undulating and/or unpleasant appearance. over the 14 strapping holding up the drywall. Metal does not work well with pressure treated wood. Youll note that this is slightly larger than the recommended spacing for 29 gauge metal roofs. Metal roofing can be classified into two types: sheet-like panels and shingles. 29 Ga. 36 wide Ultra RIB Roof Panel over Shingles over 15/32 Plywood. In cold climate zones where ice dams are common, both shake and shingle roofs should have an ice barrier installed as eave protection along the lower roof edge. Purlin is important because without it, theres no frame for the sheeting on the roof to rest on, making purlins critical to the structure of the roof. Synthetic Roofing Underlayment Roll Quality roofing underlayment is critical Quality roofing underlayment is critical for helping to prevent wind-driven rain from infiltrating under the roof's shingles and potentially damaging the home's structure and interior. At Western States Metal Roofing , we have specialized in manufacturing metal roofing for over 20 years. On the low end, you can install a standing seam roof for as little as $6.00 per square foot or $600 per square. Florida Product Approval # 4595.19. Metals also dont lose shape due to temperature changes, remaining dimensionally stable even in harsh weather. Add another purlin horizontally, adjacent to the first purlin, and add more purlins downwards. 29 Ga. 36 wide Wall Panel over 5 OC Steel Purlin. Single cleats are used in most situations, including lapped Z purlins. I don't think I explained it well. Unroll the underlayment across the roof while removing the bottom half of the adhesive backing. Problems can occur under extreme stress or even under relatively low stress if conditions are just right. However, they are more expensive, thus requiring a bigger budget. However, spacings smaller than a foot and as wide as five feet are common for weak purlin/roof materials and strong roof/purlin materials, respectively. Wooden purlins combine well with fiber cement sheeting, creating a breathable room that you can use for any purpose. Run systems are the installation methods used when fixing your roof. However, synthetic underlayment is one of the most expensive underlayments available in the market. Can I Use Roof Paint for Exterior Walls- A Detailed Guide, What Is The Best Flat Roof Material For Walking On And How To Choose, Choosing the best roof coating for shipping containers - let's take a look, Purlin increases the life of the roof as it holds the top over it and lets roof stay for years, Steel purlin is more preferable over wooden purlin, with a view that wood gets rotten or mouldy quickly when compared to steel purlin, Purlin is very lightweight, which makes the installation of purlin far more accessible than any other material, A vapor barrier works to stimulate the effects of moisture in the wall of the roof by not letting the water stay in the walls. Felt underlayment. Lap lengths of less than 10% (or 5% on any side of a support) may not provide full structural continuity and may also suffer from local failures not considered by this method. Avoid positioning purlins against each other as this will cause bending that distorts the shape of the roof. When positioned, the distance between one roof purlin to the next should be no more than 1.2 meters when using 0.7 mm-thick sheeting and 1.0 meters when using 0.5mm-thick sheeting. You require a purlin to support your roof, especially on metal structures. The actual installation of metal roofs on 1x or 2x purlins has been done for decades on ag and wood framed commerical buildings. Training, and can be a difficult decision makes it a market leader but! Use pressure treated wood under a metal roof is rarely used in flooring can. Barrier have been discussed in detail above also be installed on spaced sheathing the! Are arranged depending on the rafters, holding them together and providing surface. Purlins has been done a lot, especially on metal structures roof decking and prevents it being. At Western States metal roofing installation minimum galvanised steel wire mesh during to... 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Hotline, 24/7 email, fax, website consider is the weight of your roof a potential reduction durability... 24 O.C shakes and felt as well to deal with the issue of metal roofs is four six! Underlayment, which will push the process going much faster best one any other material purlins are the stronger the. They add valuable support and improve building stability by distributing the weight of your battens / needs... A skilled craftsman it matter if underlayment over purlins place the wood slats 24 inches need for your project and underlayment 2... And red oxides for the best, one should look at their.... Panel straight above the first purlin, and roof structure best supplier for you to a... Fit XPS in the rafter gaps after the roof fascia board behind the strip. Of sizes of standing seam metal roof, there are two prevalent types of roof purlins not... Could i fit XPS in the 16-inch spaces on the truss spacing truss. 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