No prendas el aire este verano: la lámina de $15 que le baja 15°C a tu techo

THE HOME REPAIR MANUAL — 40 numbered repairs, with the exact quantities, measurements, and times for each. https://www.constructorlibre.com/?src=yt For those tired of the black stain that reappears every winter, the leak they've patched three times, the wall whose paint is peeling from the bottom up, and the guy who looks at the wall for two minutes, uses a technical term, and quotes you thousands. It's all solved here, step by step, with numbers. ━━━━━━━━━━━━━━━━━━━━━━ In this video, I show you the RADIANT BARRIER: a sheet of polished aluminum that is stapled under the roof beams and reflects the heat that your roof is radiating onto you for nine hours a day. It is not an insulator. It's not even a millimeter thick. And it's the first thing that should be installed in most houses in this country. THE EXACT MEASUREMENTS (the ones I promised in the video): 1. AIR GAP — a minimum of 2.5 cm (one inch) between the sheet and the hot surface. Without this space, the sheet heats up by contact and becomes completely useless. This is the crucial factor. 2. OVERLAP between strips — 5 cm, and the staple every 15-20 cm on the underside of the rafters. 3. COVERAGE — it's purchased per square meter of ROOF (the sloping surface), not the floor. On a typical gable roof, it's between 15% and 20% more square meters than the floor area of ​​the house. Add the overlap. 4. RECESSED LIGHT FIXTURES — leave 8 cm of clearance around each one, without any sheeting above it. The same applies to chimneys and heater flues. 5. ORIENTATION — the shiny side MUST ALWAYS face down, stapled under the rafters. If you lay it over the insulation with the shiny side facing up, dust will settle on it and it will be ruined in two summers (the emissivity will drop from 0.05 to 0.30). 6. VENTILATION — if you use solid, unperforated roofing sheets, the attic must be ventilated. Otherwise, the steam from the house will condense against the sheets and dampen the insulation. Perforated sheets are available for laying over insulation. THE NUMBERS AND SOURCES: • Emissivity of clean aluminum: 0.03-0.05 (wood and tile: 0.90) • Reflects 95-97% of incoming radiant heat • U.S. Department of Energy: Reduces heat gain through the roof by 16% to 42%, and cooling costs by 5% to 10% in hot climates • Florida Solar Energy Center: Lowers the underside of the roof by 10-15°C • Standards: ASTM C1313 (what is a radiant barrier) and ASTM C1371 (how to measure emissivity) SAFETY, and this is serious: • A loft at midday in summer can reach 60°C. This is heatstroke temperature and it doesn't give any warning. Work early, with water available, and make sure someone knows you're up there. • ALWAYS step on the joists. The ceiling panel runs between the joists. • Aluminum conducts electricity. If there are old wires or splices made with tape, fix that BEFOREHAND. CHAPTERS 00:00 What Your Roof Is Doing to You Right Now 01:05 Where This Came From (An 1892 Thermos and the Lunar Module) 03:00 The Three Ways Heat Gets Into Your House 05:50 Why Insulation Doesn't Stop Radiation 07:30 The Real Numbers (And What It Doesn't Do) 09:15 Case 1: Roof with a Mezzanine 10:30 The Air Gap: The Point That Decides Everything 11:50 Case 2: Galvanized Sheet Metal Roof 12:40 Case 3: Concrete Roof 14:00 What They'll Try to Sell You (Paint and Bubbles) 15:30 The Two Tests You Can Do This Weekend 17:00 The Made-Up Number on the Label 18:20 The Honest Limits 20:00 The Mistake That Ruins 90% of Installations 22:00 The Step-by-Step Review What Do You Think? Do you have a concrete slab, a metal sheet, or a loft above your head? And what city are you writing from? I read all your comments and use them to create future videos. #radiantbarrier #energyefficiency #airconditioning #coolhouse #construction