Extend bootstrap row outside the container

Here is a variant of solution. You need to create absolute positioned div, include it into col-xs-6, but this container should have position: static As for screen width 1200px and more container width is 1170px, you can calculate padding-left for floating div: padding-left: calc((100% - 1170px) / 2);

.blk {
    background: lightgreen;
    width: 50%;
    position: absolute;

}
.container {
    background: tomato;
    height: 100vh;
    padding: 40px 0;
}
@media only screen and (min-width: 1200px) {
 .cell {
    position: static;
 }
 .blk {
    left: 0;
    right: 50%;
    padding-left: calc((100% - 1170px) / 2);
 }
}
<div class="container">
<div class="row">
    <div class="col-lg-6 cell">
        <div class="blk">Lorem ipsum dolor</div>
     </div>
  <div class="col-lg-6">Lorem ipsum dolor</div>
</div>
</div> 

http://www.codeply.com/go/CikO35yioi


If you use a grid and position it absolute behind your main content, you can get the background grid to be exactly the same as the foreground grid. You can then use pseudo elements to position the image to stretch to the edge of the screen.

.first .stretch-right::after {
  background: url('https://i.picsum.photos/id/802/1920/1080.jpg?hmac=6P9kWTyEU0oX0KcmjlRcGZwNc5Jb27w2_qqtsqQz-fg') no-repeat;
}
.second .stretch-left::after {
  background: url('https://i.picsum.photos/id/802/1920/1080.jpg?hmac=6P9kWTyEU0oX0KcmjlRcGZwNc5Jb27w2_qqtsqQz-fg') no-repeat;
}
.stretch-right::after {
  content: '';
  background-size: cover !important;
  background-position: center center !important;
  right: 0;
  height: 100%;
  position: absolute;
  left: 0;
}
@media (min-width: 1140px){
  .stretch-right::after {
    right: calc((-1%) - ((100vw - 1140px) / 2));
  }
}
.stretch-left::after {
  content: '';
  background-size: cover !important;
  background-position: center center !important;
  right: 0;
  height: 100%;
  position: absolute;
  left: 0;
}
@media (min-width: 1140px){
  .stretch-left::after {
    left: calc((-1%) - ((100vw - 1140px) / 2));
  }
}
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<section class="position-relative py-5 first">
  <div class="position-absolute w-100 h-100">
    <div class="container h-100 bg-container">
      <div class="row h-100 d-flex justify-content-between align-items-center">
        <div class="col-12 col-md-5 h-100 d-flex"></div>
        <div class="col-12 col-md-6 h-100 d-flex stretch-right"></div>
      </div>
    </div>
  </div>
  <div class="container">
    <div class="row d-flex justify-content-between align-items-center">
      <div class="col-12 col-md-5">
        <h1>
          Nullam dapibus neque id maximus
        </h1> 
        <p>
        Maecenas sollicitudin egestas convallis. Cras non congue ipsum. Suspendisse auctor, elit at lacinia pulvinar, quam ligula pulvinar mi, vitae ornare metus dolor non quam. Integer eget bibendum ligula. Pellentesque vel consectetur diam. In sagittis aliquam eros, at faucibus erat blandit id. Aliquam fringilla sagittis enim sed porta. Donec sed rutrum metus. Fusce nibh orci, tristique sed luctus quis, imperdiet eu nibh. In accumsan congue commodo. Vestibulum a pulvinar ante.
        </p>
      </div>
      <div class="col-12 col-md-5 bg-white">
        <h3>
        I'll stay in the grid
        </h3>
        <p>
        tristique sed luctus quis, imperdiet eu nibh. In accumsan congue commodo. Vestibulum a pulvinar ante.
        </p>
      </div>
    </div>
  </div>
</section>
<section class="position-relative py-5 second">
  <div class="position-absolute w-100 h-100">
    <div class="container h-100 bg-container">
      <div class="row h-100 d-flex justify-content-between align-items-center">
        <div class="col-12 col-md-6 h-100 d-flex stretch-left"></div>
        <div class="col-12 col-md-5 h-100 d-flex"></div>
      </div>
    </div>
  </div>
  <div class="container">
    <div class="row d-flex justify-content-between align-items-center">
      <div class="col-12 col-md-5 bg-white">
        <h3>
        I'll stay in the grid
        </h3>
        <p>
        tristique sed luctus quis, imperdiet eu nibh. In accumsan congue commodo. Vestibulum a pulvinar ante.
        </p>
      </div>
      <div class="col-12 col-md-5">
      <h1>
          Nullam dapibus neque id maximus
        </h1> 
        <p>
        Maecenas sollicitudin egestas convallis. Cras non congue ipsum. Suspendisse auctor, elit at lacinia pulvinar, quam ligula pulvinar mi, vitae ornare metus dolor non quam. Integer eget bibendum ligula. Pellentesque vel consectetur diam. In sagittis aliquam eros, at faucibus erat blandit id. Aliquam fringilla sagittis enim sed porta. Donec sed rutrum metus. Fusce nibh orci, tristique sed luctus quis, imperdiet eu nibh. In accumsan congue commodo. Vestibulum a pulvinar ante.
        </p>
        
      </div>
    </div>
  </div>
</section>

One option is to use a CSS pseudo ::before element that will resize in height along with the col-lg-6..

#main {
    background: lightgreen;
    height: 100vh;
}

#main > .row {
    height: 100vh;
}

.left {
    background: red;
    position: relative;
    top: 50%;
    transform: translateY(-50%);
}

.left:before {
    left: -999em;
    background: red;
    content: '';
    display: block;
    position: absolute;
    width: 999em;
    top: 0;
    bottom: 0;
}
<div class="container" id="main">
    <div class="row">
        <div class="col-lg-6 left">
            ..
        </div>
    </div>
</div>

http://codeply.com/go/C80RYwhWrc


Another option is to use an absolute position .container-fluid (full-width) behind the content .container that acts as a "ghost"...

.abs {
    position: absolute;
    right:0;
    top:0;
    bottom:0;
    z-index: 1;
}

<div class="container">
    <div class="row">
        <div class="col-sm-6">
            <h4>Content</h4>
        </div>
        <div class="col-sm-6">
            <!-- space over image -->
        </div>
    </div>
</div>
<div class="container-fluid abs">
    <div class="row h-100">
        <div class="col-sm-6 h-100">
            <!-- empty spacer -->
        </div>
        <div class="col-sm-6 right">
            <img src="//placehold.it/1000x400">
        </div>
    </div>
</div>

https://codeply.com/go/txUHH72f16 (Bootstrap 4)


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