{"id":448,"date":"2026-09-13T13:58:03","date_gmt":"2026-09-13T11:58:03","guid":{"rendered":"https:\/\/www.ksaerial.cz\/blog\/?p=448"},"modified":"2026-09-13T13:58:03","modified_gmt":"2026-09-13T11:58:03","slug":"hidden-defects-in-window-replacements-why-you-shouldnt-accept-work-blindly","status":"publish","type":"post","link":"https:\/\/www.ksaerial.cz\/blog\/en\/hidden-defects-in-window-replacements-why-you-shouldnt-accept-work-blindly\/","title":{"rendered":"Hidden Defects in Window Replacements: Why You Shouldn&#8217;t Accept Work &#8222;Blindly&#8220;"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">House renovation is stressful, deadlines are tight, and investors often find themselves under pressure to accept the finished work as soon as possible. Construction companies frequently claim that &#8222;everything is fine&#8220; and push for the handover protocol to be signed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We dealt with exactly such a case last week. The construction company insisted on the flawless installation of new windows. However, the owner suspected something was wrong. Rather than arguing over feelings, they called us for an independent thermographic inspection.<\/p>\n\n\n\n<figure data-wp-context=\"{&quot;galleryId&quot;:&quot;6ab09aeb75a26&quot;}\" data-wp-interactive=\"core\/gallery\" class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6ab09aeb7697e&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6ab09aeb7697e\" class=\"wp-block-image size-large wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"1005\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" data-id=\"453\" src=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/podminky_mereni-2-1024x1005.jpg\" alt=\"\" class=\"wp-image-453\" srcset=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/podminky_mereni-2-1024x1005.jpg 1024w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/podminky_mereni-2-300x295.jpg 300w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/podminky_mereni-2-767x753.jpg 767w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/podminky_mereni-2.jpg 1239w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n\n\n\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6ab09aeb76cbc&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6ab09aeb76cbc\" class=\"wp-block-image size-full wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"531\" height=\"370\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" data-id=\"452\" src=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/dum-1.png\" alt=\"\" class=\"wp-image-452\" srcset=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/dum-1.png 531w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/dum-1-300x209.png 300w\" sizes=\"auto, (max-width: 531px) 100vw, 531px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Fog: The Enemy of Thermography (Or Why We Made Two Trips)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Strict conditions must be met for accurate thermal camera measurement. When I first arrived at the site, I was greeted by thick fog. Although it would have been easy to &#8222;send the drone up,&#8220; take a few photos, and issue an invoice, that would not be a professional approach.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Water in the fog absorbs infrared radiation, and the results would be distorted, blurred, and useless for a warranty claim. Instead of measuring, I called off the operation. Data quality is our top priority. We returned only when the conditions were ideal\u2014overcast, windless, and with a sufficient temperature difference between the interior and exterior (over 14 \u00b0C).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Did the Aerial Inspection Reveal?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Thanks to the top-tier camera on the DJI Matrice 4T drone, we quickly obtained data that spoke clearly. No guesswork, just physical facts. The inspection focused on the window installations, and the results did not please the investor (and certainly not the construction company):<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Massive thermal bridges:<\/strong> While the surrounding facade had a temperature of around 7 \u00b0C, the window lintels and jambs glowed on the thermogram at nearly 12 \u00b0C. This means heat from the inside was massively escaping outdoors.<\/li>\n\n\n\n<li><strong>Air leaks through the foam:<\/strong> The images revealed an inhomogeneous temperature field. Simply put: the mounting foam was degraded, lacked protective sealing tapes, and air was flowing straight through it into the masonry.<\/li>\n\n\n\n<li><strong>Heat transfer into the masonry:<\/strong> Near the bathroom window, the masonry was heating up to 13.3 \u00b0C! In winter, water would condense on the inner side of this spot, leading to mold growth.<\/li>\n<\/ul>\n\n\n\n<figure data-wp-context=\"{&quot;galleryId&quot;:&quot;6ab09aeb77824&quot;}\" data-wp-interactive=\"core\/gallery\" class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6ab09aeb77a3c&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6ab09aeb77a3c\" class=\"wp-block-image size-full wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"801\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" data-id=\"455\" src=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez1-1-768x801-1.jpg\" alt=\"\" class=\"wp-image-455\" srcset=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez1-1-768x801-1.jpg 768w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez1-1-768x801-1-288x300.jpg 288w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n\n\n\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6ab09aeb77d18&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6ab09aeb77d18\" class=\"wp-block-image size-full wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"732\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" data-id=\"454\" src=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez2-768x732-1.png\" alt=\"\" class=\"wp-image-454\" srcset=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez2-768x732-1.png 768w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/nalez2-768x732-1-300x286.png 300w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Verdict: Technically Non-Compliant<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The output of our measurement was a detailed report clearly stating that the condition was unsatisfactory. The missing external insulation of the window reveals and the unprotected connection joints cause heat losses that would cost the owner thousands of crowns annually, not to mention the costs of future mold remediation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thanks to our measurement, the investor now has bulletproof evidence for a warranty claim. The construction company cannot argue against hard data and thermal images. They must rectify the situation before everything is &#8222;hidden&#8220; under the final facade.<\/p>\n\n\n\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6ab09aeb78164&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6ab09aeb78164\" class=\"wp-block-image size-full wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"883\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" src=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/zaver-1024x883-1.jpg\" alt=\"\" class=\"wp-image-456\" srcset=\"https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/zaver-1024x883-1.jpg 1024w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/zaver-1024x883-1-300x259.jpg 300w, https:\/\/www.ksaerial.cz\/blog\/wp-content\/uploads\/2026\/09\/zaver-1024x883-1-768x662.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Are You Carrying Out Construction or Renovation?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">It pays to have an independent quality check before defects are covered up. You will save hundreds of thousands in future repairs and have the certainty that you are paying for high-quality work.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Do not leave your investment to chance. <a href=\"https:\/\/www.ksaerial.cz\/en.html#contact\">Let us inspect it.<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>House renovation is stressful, deadlines are tight, and investors often find themselves under pressure to accept the finished work as soon as possible. Construction companies frequently claim that &#8222;everything is fine&#8220; and push for the handover protocol to be signed. We dealt with exactly such a case last week. The construction company insisted on the&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":324,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","iawp_total_views":1,"footnotes":""},"categories":[106,174],"tags":[181,117,179,183,176],"class_list":["post-448","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-projects","category-thermography","tag-complaint","tag-m4t-en","tag-property_inspection","tag-thermal_bridge","tag-thermography"],"_links":{"self":[{"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/posts\/448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/comments?post=448"}],"version-history":[{"count":1,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/posts\/448\/revisions"}],"predecessor-version":[{"id":457,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/posts\/448\/revisions\/457"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/media\/324"}],"wp:attachment":[{"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/media?parent=448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/categories?post=448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ksaerial.cz\/blog\/wp-json\/wp\/v2\/tags?post=448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}