1 d
How much weight can a pressure treated 4x4 hold vertically?
Follow
11
How much weight can a pressure treated 4x4 hold vertically?
White UltraShieldTM long-life finish delivers excellent corrosion protection. I would use this number up till the point that member reached 8' of vertical hold without diagonal bracing. These timbers are pressure treated in order to protect it from termites, fungal decay, and rot. The x-axis refers to the "strong" axis of bending, except in the case of 3-2x4's bolted together, where the y-axis is stronger (see Fig Fig. Long-Term Savings The initial investment in pressure treated wood can lead to long-term cost savings. Explore More on homedepot Bath. Vertical sleeve gastrectomy is surgery to help with weight los. In this article, you will learn the factors that affect how much a 2×4 can hold horizontally. You never specified what you are putting on it other than 2500 lbs. However, if placed flat. Learn all about acetyl-l-carnitine and other alternative medicines at HowStuffWorks. a 4x6 or 6x6 gives you more meat to work with. Made of southern yellow pine. Tables 4, 5, and 6 contain design loads for 6x, 8x, 10x. I've tried to find a load calculator to determine the capacity of such a. A 4x4 with a horizontal orientation is expected to bear loads w. Color, grain pattern and texture will vary as well. For ground contact use. High humidity levels in the storage room can cause pressure-treated wood to absorb moisture from the air unevenly, leading to warping. The markets are discounting mechanisms but I am not sure what the charts of XLU are discounting. A 2×4 can hold around 1000 pounds vertically because the weight is not against the grain. live load (temporary), and the type of wood. This allows plywood to support heavier loads. Finally, here is a similar question from DIYChatroom Wood bears a toleration of roughly 625 pounds per square inch (PSI) of a compression load. A standard 2×4 can hold up to 40 pounds per linear foot when installed vertically, and 15 pounds per linear foot when installed horizontally. Weight Capacity Comparison 6×6 porch roof posts have a greater weight-bearing capacity than 4×4 posts. Some homeowners are surprised when gaps appear in their once tight deck only. The 4x4 is also stronger because it is one piece. Pressure treated for ground contact use applications; 4 in x 8 ft. The weight a 4x4 can hold depends on several factors, including wood species, grade, length, height, moisture content, grain orientation, condition, and load type. To make a proper 4×4 weight horizontal option, it has to determine how much weight should be supportive. Therefore, the table below also covers the maximum weight in pounds for 4"x 6" and 6"x 6" as well Post Length 1 Lumber. Products and technology that help people design and build safer, stronger homes, buildings, and communities. Feb 9, 2014 · An ~8ft long beam sits horizontally. A 2×4 placed vertically - a stud - can hold around 1670 pounds when spaced at 16" on center for SPF lumber. The table below reflects the current code. It is pre-assembled for quick and easy installation. When used as a post set in 2 feet of concrete a minimum of 12 inches wide how much weight will a 10 foot long 4x4 pressure treated post handle? I have an old cedar deck, and most of the decking and vertical support posts are rotted out. The compressive strength of a 4x4 varies depending on the specific type and. Screw the pieces to the bottom of the post it will give you a base to make it stand alone. Monitor the alignment using a level and make adjustments as necessary. For example, a Douglas Fir-Larch 4×6 post can support up to 10,701 pounds for a 2-foot post length, while a Hem-Fir 4×6 post can support up to 7,155 pounds for the same length. 4×4 weight for treated wood will be approximately 05% more than the 4×4 weight for untreated wood from the same tree species after drying. It's kind of technical, though, from what I can tell. For instance, a pressure-treated 4×6 made from Southern Yellow Pine can support a maximum weight of up to 4,000 lbs when placed on edge and spanning an eight-foot distance. Plywood is graded based on the quality of its veneers and the number of defects present. Lumber Weights Kiln Dried Pressure Treated And Green Crate, 45% OFF. Find 4-in x 4-in 8-ft pressure treated lumber at Lowe's today. It is pre-assembled for quick and easy installation. As plywood is often used as a load bearer, you may be concerned about how much of a load plywood can bear. A perfect 4x6x8 can hold up to 32,000 pounds of vertical weight. Steel can bare 30,000 PSI of a compression load. Expert Advice On Improving Your Home. A 2×4 can hold around 1000 pounds vertically because the weight is not against the grain. The pallet calculator can easily find the maximum number of packages 📦 you can fit on a pallet paired with the package placement needed to achieve that. We would like to show you a description here but the site won't allow us. By considering the species of wood, the grade of wood, and the size of lumber, you can determine how much weight a pressure-treated 4x4 can hold vertically. TikTok has seen its short-form video feed copied by a host of competitors, from Instagram to Snap to YouTube and even Netflix. Steel can bear 30,000 PSI of a compression load. Watch this video to find out about the advantages of using KDAT, or Kiln Dried After Treatment, pressure treated lumber which reduces shrinkage and warping. How much does a pressure treated 6 by 6 weigh per foot? A pressure treated 6x6 usually weighs around 3 A fence with 4×4 fence posts standing vertically and properly anchored in the ground can hold a weight-bearing load of approximately 10,000 pounds. (TSXV:VERT) ("Vertical" or "the Company") announces that. The framing consists of 2x4's. Responsibly manufactured from renewable southern yellow pine, this. Contact Type: Ground contact. No two pieces of lumber are the same. Comprehensive table shows the weight of 2x6 lumber by wood species and board length. Im building a pond - Answered by a verified Structural Engineer to hang a sky chair on patio. Treated for ground contact, they are ideal for a variety of applications, including retaining walls, deck, playsets, landscaping, stair support posts, and walkways. The heaviest kid is 120 lbs. Dec 6, 2023 · Horizontally, a 2×4 supports 20-40 pounds per foot if weight is evenly spread. These timbers are pressure treated in order to protect it from termites, fungal decay, and rot. #2 Pressure-Treated Ground Contact Southern Pine Wood Post 4220254 on Page 4. The compressive strength of a 4x4 varies depending on the specific type and. A 4x4 column is a lot stronger than a 4x4 beam. The compressive strength of a 4x4 varies depending on the specific type and. Responsibly manufactured from renewable southern yellow pine, this. Weight capacity is influenced by factors like wood species, grade, and moisture. Discover the benefits of planting and conserving trees with 8 Billion Trees. I would frame the sides in the same manner - 4x4's, with a vertical 4x4 in each of the corners. Concrete can bare 3,000 PSI of a compression load. Specially the treated kind at box stores. It only takes 3 of the 16 inch pieces. This in combination with the post connectors to. Steel posts can withstand 360,000 pounds of force; with vinyl withstanding 165,000 pounds. O, I forgot, I will be supporting the concrete on a 3/4" plywood sheet with holes and all thread as mentioned before. Thanks anyone everyone for thoughtful answers Nov 18, 2023 · Comprehensive table shows the weight of 4x4 lumber by wood species and board length. For instance, a 4×4 made of pressure-treated pine with a length of 8 feet and proper support can typically hold a. How can I calculate the maximum load a rectangular horizontal wooden beam of dimensions L x H x W can safely support if the beam is adequately supported at both ends? assuming worst case - load concentrated at center for commonly available types of wood (e Spruce) wood load-bearing Share Improve this question asked Oct 13, 2015 at 14:48. in my garage I have 2x6s spaced 24 inches apart. celebrity phun extra Do not pick the cheapest. A 4×6 made of pressure-treated wood can hold around 800 to 1000 pounds, while a steel 4×6 can support up to 2000 pounds. Vertically, a 4×4 should support 4300 pounds but can hold significantly more. According to building codes, there is no clear answer on when you should install a 4×4 vs However, experienced contractors will tell you that a 4×4 post simply can't carry the heavy load that many porches require. AC2® brand treated wood products use MicroPro® technology, which is a revolutionary way to pressure treat wood for decks, fences, landscaping, and general construction uses. Sep 16, 2023 · Wiki User Best Answer. How Much Weight Can A Pressure Treated 4x4 Hold Vertically. It is now just days before Disrupt, which means the TechCrunch hive is buzzing InvestorPlace - Stock Market News, Stock Advice & Trading Tips The best vertical farming stocks have been in a deep correction mode InvestorPlace - Stock Market N. People make use of the 4×4 wooden beams for supporting the weight horizontally by placing them on the corners for supporting the tank or the deck without having to. For example, can support up to 295 pounds. 4″ x 4″ are the nominal dimensions of the board. Apr 8, 2021 · How much weight can a 2×6 support vertically? A 2×6 used vertically as a stud in a sheathed wall with blocking at prescribed intervals will support 7061lbs before buckling. This is because lag bolts are so powerful, they can easily damage the medium you're. When installing something like decking, it's recommended to fasten the planks as tight as possible to the prior board, since a natural gap is going to occur anyways. The untreated weight per foot is 3, resulting in a 4x4x8 weight of 25. Sep 14, 2023 · How much does a pressure treated 6 by 6 weigh per foot? A pressure treated 6x6 usually weighs around 3. I do not know if it is pressure treated or not. To do that, you need to know, "how much weight can a 4×4 hold?" 4×4 can hold up to 4,000 pounds when laying horizontally with the right support. Help my basement may not be structurally sound. For instance, a 4×4 made of pressure-treated pine with a length of 8 feet and proper support can typically hold a. Ranolazine: learn about side effects, dosage, special precautions, and more on MedlinePlus Ranolazine is used alone or with other medications to treat chronic angina (ongoing chest. personalumbrella I would like to have the beam be at least a 10 foot beam. The arch (contained within these three) is stro. Most 4×6 beams are about 16 ft long, but you can get the length that meets your needs. Apr 6, 2013 · Weight bearing load of a vertical 4x4 piece of wood, compared to a 6x6. Ponderosa Pine is typically used indoors unless specifically treated for outdoor use. The amount of weight 2×4 can hold without sagging, bending or breaking depends on the lumber's orientation and the span, load, species, and grade. AITC SP-48 Roof Beams Construction Load. Societal pressure and the consistent trauma of navigating the world as a Black person can make it difficult to discuss and treat depression within the Black community Are foot scrapers safe for my feet? Find out if foot scrapers are safe for your feet at HowStuffWorks. As plywood is often used as a load bearer, you may be concerned about how much of a load plywood can bear. Step 6 : Multiply by the length of the 6×6. I would also need to put about 30 2x2x12 on top of that to increase shading effect. The amount of weight 2×4 can hold without sagging, bending or breaking depends on the lumber's orientation and the span, load, species, and grade. Help my basement may not be structurally sound. In this article, you will learn how much weight a 2×6 can safely. I do not know the grade. We would like to show you a description here but the site won’t allow us. It uses advanced wood preservative technology that is low VOC, low eco-toxicity and certified as an Environmentally Preferable Product. The vertical load capacity of a "plain" wooden post will depend on its height. with strength chart & capacity calculator This lumber is pressure treated in order to protect it from termites, fungal decay, and rot What is the weight of 10' 4x4? by Kevin | Jun 12, 2024 Answer This Question Ive used these for my raised shed to hold up the 2x6 joists. An 8-foot length of 2×4 that can support 1,000 pounds vertically will sag unacceptably under 200 pounds vertically without any support in the middle. Concerta, which treats ADHD, can cause side effects such as weight loss and anger. May 14, 2023 · Horizontally, a 2×4 can support 20-40 lbs of evenly distributed weight. Ranolazine: learn about side effects, dosage, special precautions, and more on MedlinePlus Ranolazine is used alone or with other medications to treat chronic angina (ongoing chest. I would also need to put about 30 2x2x12 on top of that to increase shading effect. craigslist nashvillr 4×4 board weighs about 29, an F-150 can carry 44 boards. Free standing 4x4 post NEW Cut an 8 foot 2x4 in to 16 inch pieces. We would like to show you a description here but the site won’t allow us. 8 I'm in the process of installing a handrail here and the former owner put these pressure-treated 4x4 posts without cutting them first. High humidity levels in the storage room can cause pressure-treated wood to absorb moisture from the air unevenly, leading to warping. The amount of weight 2×4 can hold without sagging, bending or breaking depends on the lumber's orientation and the span, load, species, and grade. How Much Weight Can a 4X6X8 Hold Horizontally. First off the get dry and brittle over time, twist and bow. Watch this video for tips on how to clean, repair, and finish a pressure treated wood deck to keep it looking great for years to come. We would like to show you a description here but the site won't allow us. The thicker the plywood, the more weight it can hold. A 4×6 made of pressure-treated wood can hold around 800 to 1000 pounds, while a steel 4×6 can support up to 2000 pounds. 126 posts · Joined 2016 Lol!! 4x4's are the WORST type of building material. It would be a midpoint load. May 28, 2010 · The maximum weight that a 6x6 lumber post can hold depends on several factors such as the type and grade of lumber, the length of the post, and the spacing between posts. A typical 4x4x8 treated wood post will weight around 38 pounds. Need to get it over stairs 600lb IH mill (Table/head removed) and 12x36 1000lb lathe.
Post Opinion
Like
What Girls & Guys Said
Opinion
9Opinion
How Much Weight Can a 4X6X8 Hold Horizontally. An 8' 4x4 can support roughly 6500lbs. Anchoring Landscape Lumber (4×4) to the Ground. You should always use the smallest lag bolt possible for the weight of your project. Using a long 4×6 beam on a swing set will require you to add support beams at the middle part of the. Generally, plywood can support up to hundreds of pounds in weight. Douglas fir, without treatment, can last 10 to 15 years. However, the actual weight capacity of a 2×4 can vary depending on the species of wood, the grade of the lumber, and the condition of the 2×4. When used as a post set in 2 feet of concrete a minimum of 12 inches wide how much weight will a 10 foot long 4x4 pressure treated post handle? 2 feet of the post will be incorporated into a structure, but that can be ignored for the moment Not to be vague but a 4x4 has a lot of vertical support. The 4x4 would be what provided resistance to flexing, at least as much as it could. If the wood absorbs the water droplets, it will take paint. Nov 18, 2023 · After drying, the weight of a piece of pressure-treated 6×6 lumber will be approximately 05% more than the weight of a piece of untreated lumber of the same length and from the same tree species. This lumber is pressure treated in order to protect it from termites, fungal decay, and rot. 7556 posts · Joined 2006 Wood bares the toleration of roughly 625 pounds per square inch (PSI) of a compression load. However, the post will typically buckle under much lower load than the axial compression. find ups dropoff Used vertically as a post, an 8’ 4×4 can support about 6,000 PSI before buckling, and even more if correctly braced. It's kind of technical, though, from what I can tell. 6×6 in 133~155 lbs Remember that a 4×4 post is not actually 4 inches by 4 inches, each side will measure between 375 inches. Vertically, a 4x4 can support 4,300 pounds but can hold significantly more. Still, suppose you're dealing with various load types, such as point load, uniformly distributed load, or a combination of both. This rig is indoors only. meaning if I hang something from the middle of that elongated 4x4x8 what is the maximum weight it could. Generally, plywood can support up to hundreds of pounds in weight. However, on average, a 6x6 lumber post can hold up to 30,000 pounds of vertical load. Acebutolol also is used to treat an irre. Specifically, if it's laid vertically, it can support up to 500 lbs of centralized weight, and up to 1,000 lbs of evenly distributed weight. 4×4 weight for treated wood will be approximately 05% more than the 4×4 weight for untreated wood from the same tree species after drying. How can we decide how much weight a beam can carry? Quora. Laid horizontally flat, a 2×6 can only support 4 lbs per linear foot. price of gas in quebec However, if placed flat. (105) Questions & Answers (5) Hover Image to Zoom Pressure treated for protection against termites, fungus, and rot. 4 %âăĎÓ 1 0 obj /Type/ExtGState /SM 0. The untreated weight per foot is 3, resulting in a 4x4x8 weight of 25. Also, a 2×4 can hold a uniform load of 30-40. Finally, here is a similar question from DIYChatroom Wood bears a toleration of roughly 625 pounds per square inch (PSI) of a compression load. How much weight can a pressure treated 4×6 hold vertically? 4×4 can hold up to 4,000 pounds when laying horizontally with the right support. So, let's look at some rough examples: For a 2' (0. Lumber Grade: #2 & Btr. 3) 1/2" hole drilled vertically through the beam at each load application point. Such calculations would hold if, for instance, the load is square. Watch this video for tips on when to and not to leave a gap between pressure treated wood deck boards when building a new deck or replacing old decking. May 20, 2019 · What the instructions are referring is the pull load against the post, not the vertical load. 51 ground contact rated) were between 25 and 30# depending on their moisture content. The 4x4 is also stronger because it is one piece. The legs on the bracket are 4x4 by 12 feet and the beam would be a 4x6. However, on average, a 6x6 lumber post can hold up to 30,000 pounds of vertical load. I think this is referred to as a brace pocket. However, that number can change depending on a variety of important elements. Assuming #2 grade, the. Made of southern yellow pine. jay sekulow live today watch online This is enough to maintain the position of a house. Allowing for buckling, allowable compressive stress is roughly 475 psi, Area is 30 sq in, so the allowable force in the post is 14,300 lb. The surgeon removes a large portion of your stomach. Frequently Asked Questions Of How Much Weight Can Wood Hold Calculator How Much Weight Can A 2×4 Hold Horizontally? A 2×4 can typically hold up to 450 pounds horizontally, depending on span and load distribution. How Much Weight Can A 4X4 Hold Vertically Horizontally?, 4-in x 4-in x 8-ft Stained Ground Contact Wood Pressure Treated Lumber Search for: how much weight can a pressure treated 4x4 hold vertically. Rot-resistant to hold up to the elements. According the diagram above - the safe loads for 4x4 Douglas Fir-Larch Columns with lengths 75 m) are approximately 8 kips (35 A 2×6 will hold 4 pounds per linear foot horizontally and 53 pounds per linear foot on its edge. Or, bury them 3-4 feet deep and bolt 2x2 or 2x4 lumber to them aboveground to get to 7 feet (or more) above ground level. InvestorPlace - Stock Market N. Vertical: Average 2×4: Approximately 600 pounds, assuming standard grade wood and evenly distributed load. Standing upright, a 4×4 can support upwards of 4,300 lbs, provided there are multiple, properly spaced 4x4s. Thus, the point of contact between two 4x4's will support 6,000 lbs.
A sheet of 3/4 plywood using 24-inch center floor joists can hold 170 pounds per square foot, you can increase the capacity by using 16 inch or even more by using 12 inches on center floor joists. A typical 4x4x8 treated wood post will weight around 38 pounds. What is weight of a 14' x 22' wood deck? Weight of pressure treated lumberDepending on it's intended use, pressure treated wood only weighs between 6 pounds per cubic foot more than the. the original number will hold. However, if the post is a stronger grade, the strength goes up quite. It is now just days before Disrupt, which means the TechCrunch hive is buzzing InvestorPlace - Stock Market News, Stock Advice & Trading Tips The best vertical farming stocks have been in a deep correction mode InvestorPlace - Stock Market N. So, how much weight can a 2×6 hold? A 2×6 will hold 4 pounds per linear foot horizontally and 53 pounds per linear foot on its edge. Factors Affecting Vertical Capacity: Load duration, dead load (permanent) vs. abc news live anchors Supported at 16" centers and the load jumps to 4,000lbs. Screw the pieces to the bottom of the post it will give you a base to make it stand alone. What Vertical Member Are Used To Support Girders And. AITC SP-49 Floor Beams Live Load. second hand cars autotrader In that case, you'll need to use a beam calculator to determine the accurate weight limit of your wood. 3/4 plywood is often recommended for use as a shed floor. of end grain support. So then, if your deck has 100 square feet, it'll support up to 5000 pounds. 5 inches square, and plugging these numbers into the formula, we get: Web #3 · apr 13, 2009 i used pressure treated southern pine, grade 1. In this article, you will learn the factors that affect how much a 2×4 can hold horizontally. According the diagram above - the safe loads for 4x4 Douglas Fir-Larch Columns with lengths 75 m) are approximately 8 kips (35 A 2×6 will hold 4 pounds per linear foot horizontally and 53 pounds per linear foot on its edge. In this article, you will learn how much weight a 2×6 can safely. att email account login I would like to cut a new 4x4 post into 1ft pieces and put on top of existing ones. I would also need to put about 30 2x2x12 on top of that to increase shading effect. Screw the pieces to the bottom of the post it will give you a base to make it stand alone. The amount of weight that a 4×4 can hold depends on several factors like wood grade, species, and load type. How Much Weight Can A 4X4 Hold Vertically Horizontally?, 4-in x 4-in x 8-ft Stained Ground Contact Wood Pressure Treated Lumber Apr 25, 2023 · 1″ As you can see, a 1/2″ plywood can support up to 35 pounds per square foot.
When installing something like decking, it's recommended to fasten the planks as tight as possible to the prior board, since a natural gap is going to occur anyways. Sep 18, 2023 · However, it is essential to determine the maximum weight capacity of a 4×6 before loading it up. The load-bearing capacity of a 4x4 is influenced by factors such as wood species, grade, and load type. Find the best pressure treated lumber grades for durability. To determine the weight capacity of vertical tubes, experiments can be done with. The 6×6 post will handle about. To contrast, the weight of 2X4X8 (wet, sappy,. Hi, I need to get my lathe/mill outta the basement. To recap, how much weight a 4×4 can hold is mainly determined by its position. meaning if I hang something from the middle of that elongated 4x4x8 what is the maximum weight it could take. Jun 2, 2022 · As soon as you go to load your 4x4s in your truck, though, knowing the factors that affect the weight of your boards is going to be crucial for safe and efficient transportation. A grade 5 9/16th bolt can hold roughly 4000lbs shear. Approved for ground contact. MicroPro® technology offers many. unit conversion calculator to convert the following units Acceleration, area, torque, electrical, energy, force, force / length, length, light, mass, mass flow, density, power, pressure, stress, temperature, time, velocity, viscosity, volume Pressure treated (. Hammer the post in place with rebar through the holes. But doubling that thickness to 1″ of plywood supports up to 164 pounds per square foot. bacb monthly verification form multiple supervisors 2022 4x4x8 pressure treated stella jones. I was going to use screws to hold the beams together. pressure treated 4x4 x 10. Otherwise buy 10 or 12 foot wooden posts if you want 7-8 feet above ground and you want them to stay put. Pressure-treated 4x4s are a popular choice for outdoor projects, but itâ  s important to understand their load capacity before using them in a construction project. The preservative in the wood does not add much weight. I was going to span 12 ft between supports and cantilever 4 ft but I now would prefer to put the supports at each end. The surgeon removes a large portion of your stomach. I would also need to put about 30 2x2x12 on top of that to increase shading effect. An 8-foot length of 2×4 that can support 1,000 pounds vertically will sag unacceptably under 200 pounds vertically without any support in the middle. If you have attention deficit hyperactivity diso. The untreated weight per foot is 3, resulting in a 4x4x8 weight of 25. Many municipal and state building codes require this critical structural treatment when posts in a structural application are put into the ground. Im building a pond - Answered by a verified Structural Engineer to hang a sky chair on patio. Marine plywood and MDF can sustain several hundred pounds per sheet, whereas cheaper types of plywood can typically bear anywhere between 5 and 50 pounds per sheet. Position each piece to ensure that it will fit properly. Pressure-treated 4x4s are a popular choice for outdoor projects, but itâ  s important to understand their load capacity before using them in a construction project. This is because the 2x4s are not as wide, and therefore cannot bear as much weight. Vertically, a 4×4 should support 4300 pounds but can hold significantly more. That being said, a post can hold a tremendous amount of load! If a particular species of wood can support 1,000 psi, then an 8x8 post can hold 64,000 pounds! The limiting factor (reason to up-size) will likely be aesthetics and/or the number or type of joints needed. spin the wheel nba teams Drop a few beads of water on the wooden board. How Much Weight Can A 4X4 Hold Vertically. In stock and ready for local delivery or in store pickup. Made of southern yellow pine. The tables bellows indicates allowable concentric loads for steel pipe columns: The tubing that you suggested 1800mm x 25mm x 25mm with wall thickness of 3mm can be converted to an approximate dimension of 72" long, 1"x1" square outside size and a wall thickness of 0 The suggests that such tubing supported at the very ends would experience a deflection of almost a half an inch with a 100 pound load applied right at. Limited lifetime warranty x 4 in Pressure-treated for long life. Average equilibrium for interior wood in US ~8%. 2) Actual cross section dimensions of the beam is 35". Addiction to any drug—be it alcohol, tobacco, opioids or illicit drugs, like cocaine—is a chronic disease that cau. Here's how taking more vitamin D might help weight loss According to the founder of Singapore-based telehealth platform Ora, 90% of its patients are less than 39 years old and have not been treated for their conditions offline Hernias are bulges that occur when increased pressure in the body causes an organ to push through weak areas of muscle or tissue. With so much water in the wood grain from the treatment process the weight of a wood post can vary a lot. How much weight can a 6x6 post hold Nov 22, 2016 · 21 1 1 2 The critical missing piece to your question is span. Otherwise buy 10 or 12 foot wooden posts if you want 7-8 feet above ground and you want them to stay put. Pneumothorax occurs when air gets trapped between a lung and the chest wall.