diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 9213469..bc8135f 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -1,6 +1,5 @@
 <?php
 
-use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\DrupalKernel;
 use Drupal\Core\Config\BootstrapConfigStorageFactory;
@@ -8,9 +7,12 @@
 use Drupal\Core\Database\DatabaseExceptionWrapper;
 use Drupal\Core\Database\Install\TaskException;
 use Drupal\Core\Form\FormState;
-use Drupal\Core\Installer\Exception\AlreadyInstalledException;
+use Drupal\Core\Installer\Exception\ActiveConfigurationExists;
+use Drupal\Core\Installer\Exception\DatabaseAlreadyPopulatedException;
+use Drupal\Core\Installer\Exception\InstallationTasksCompleted;
 use Drupal\Core\Installer\Exception\InstallerException;
 use Drupal\Core\Installer\Exception\NoProfilesException;
+use Drupal\Core\Installer\Exception\SettingsAlreadyExistsException;
 use Drupal\Core\Installer\InstallerKernel;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManager;
@@ -480,8 +482,7 @@ function install_begin_request($class_loader, &$install_state) {
     // Do not install over a configured settings.php.
     if (Database::getConnectionInfo()) {
       $translator = $container->get('string_translation');
-      throw new AlreadyInstalledException($translator,
-        $translator->translate('Configured settings.php already exists.'));
+      throw new SettingsAlreadyExistsException($translator);
     }
   }
 
@@ -491,8 +492,7 @@ function install_begin_request($class_loader, &$install_state) {
     if (!empty($config)) {
       $task = NULL;
       $translator = $container->get('string_translation');
-      throw new AlreadyInstalledException($translator,
-        $translator->translate('Active configuration already exists.'));
+      throw new ActiveConfigurationExists($translator);
     }
   }
 
@@ -1074,8 +1074,7 @@ function install_verify_completed_task() {
   if (isset($task)) {
     if ($task == 'done') {
       $translator = \Drupal::service('string_translation');
-      throw new AlreadyInstalledException($translator,
-        $translator->translate('Installation tasks have already been completed.'));
+      throw new InstallationTasksCompleted($translator);
     }
     return $task;
   }
@@ -1113,8 +1112,7 @@ function install_verify_database_ready() {
   if ($database = Database::getConnectionInfo()) {
     if (Database::getConnection()->schema()->tableExists($table)) {
       $translator = \Drupal::service('string_translation');
-      throw new AlreadyInstalledException($translator,
-        $translator->translate('Database is already populated.'));
+      throw new DatabaseAlreadyPopulatedException($translator);
     }
   }
 }
diff --git a/core/lib/Drupal/Core/Installer/Exception/ActiveConfigurationExists.php b/core/lib/Drupal/Core/Installer/Exception/ActiveConfigurationExists.php
new file mode 100644
index 0000000..d210144
--- /dev/null
+++ b/core/lib/Drupal/Core/Installer/Exception/ActiveConfigurationExists.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Installer\Exception\ActiveConfigurationExists.
+ */
+
+namespace Drupal\Core\Installer\Exception;
+
+use Drupal\Core\StringTranslation\TranslationInterface;
+
+/**
+ * Exception thrown if Drupal is installed already.
+ */
+class ActiveConfigurationExists extends AlreadyInstalledException {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(TranslationInterface $string_translation) {
+    $this->specificMessage = 'Active configuration already exists.';
+
+    parent::__construct($string_translation);
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Installer/Exception/AlreadyInstalledException.php b/core/lib/Drupal/Core/Installer/Exception/AlreadyInstalledException.php
index 4c602e5..e57c165 100644
--- a/core/lib/Drupal/Core/Installer/Exception/AlreadyInstalledException.php
+++ b/core/lib/Drupal/Core/Installer/Exception/AlreadyInstalledException.php
@@ -12,24 +12,28 @@
 /**
  * Exception thrown if Drupal is installed already.
  */
-class AlreadyInstalledException extends InstallerException {
+abstract class AlreadyInstalledException extends InstallerException {
+
+  /**
+   * @var string
+   *  A specific message set from a class implementing this Exception.
+   */
+  protected $specificMessage = '';
 
   /**
    * Constructs a new "already installed" exception.
    *
    * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
    *   The string translation manager.
-   * @param string
-   *   Description of why it was determined that Drupal was already installed.
    */
-  public function __construct(TranslationInterface $string_translation, $detail = '') {
+  public function __construct(TranslationInterface $string_translation) {
     $this->stringTranslation = $string_translation;
-    $title = $this->t('Drupal already installed');
+    $title = $this->t('Drupal already installed.');
+
     $message = "<ul>\n";
-    if ($detail) {
-      $message .= "<li>$detail</li>\n";
+    if ($message !== '') {
+      $message .= $this->t('<li>' . $this->specificMessage . '</li>');
     }
-
     $message .= $this->t('<li>To start over, you must empty your existing database and copy <em>default.settings.php</em> over <em>settings.php</em>.</li>
 <li>To upgrade an existing installation, proceed to the <a href="!update-url">update script</a>.</li>
 <li>View your <a href="!base-url">existing site</a>.</li>
@@ -37,6 +41,7 @@ public function __construct(TranslationInterface $string_translation, $detail =
       '!base-url' => $GLOBALS['base_url'],
       '!update-url' => $GLOBALS['base_path'] . 'update.php',
     ));
+
     parent::__construct($message, $title);
   }
 
diff --git a/core/lib/Drupal/Core/Installer/Exception/DatabaseAlreadyPopulatedException.php b/core/lib/Drupal/Core/Installer/Exception/DatabaseAlreadyPopulatedException.php
new file mode 100644
index 0000000..08c5923
--- /dev/null
+++ b/core/lib/Drupal/Core/Installer/Exception/DatabaseAlreadyPopulatedException.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Installer\Exception\DatabaseAlreadyPopulatedException.
+ */
+
+namespace Drupal\Core\Installer\Exception;
+
+use Drupal\Core\StringTranslation\TranslationInterface;
+
+/**
+ * Exception thrown if Drupal is installed already.
+ */
+class DatabaseAlreadyPopulatedException extends AlreadyInstalledException {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(TranslationInterface $string_translation) {
+    $this->specificMessage = 'Database is already populated.';
+
+    parent::__construct($string_translation);
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Installer/Exception/InstallationTasksCompleted.php b/core/lib/Drupal/Core/Installer/Exception/InstallationTasksCompleted.php
new file mode 100644
index 0000000..fb0c39f
--- /dev/null
+++ b/core/lib/Drupal/Core/Installer/Exception/InstallationTasksCompleted.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Installer\Exception\InstallationTasksCompleted.
+ */
+
+namespace Drupal\Core\Installer\Exception;
+
+use Drupal\Core\StringTranslation\TranslationInterface;
+
+/**
+ * Exception thrown if Drupal is installed already.
+ */
+class InstallationTasksCompleted extends AlreadyInstalledException {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(TranslationInterface $string_translation) {
+    $this->specificMessage = 'Installation tasks have already been completed.';
+
+    parent::__construct($string_translation);
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Installer/Exception/SettingsAlreadyExistsException.php b/core/lib/Drupal/Core/Installer/Exception/SettingsAlreadyExistsException.php
new file mode 100644
index 0000000..3d52053
--- /dev/null
+++ b/core/lib/Drupal/Core/Installer/Exception/SettingsAlreadyExistsException.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Installer\Exception\SettingsAlreadyExistsException.
+ */
+
+namespace Drupal\Core\Installer\Exception;
+
+use Drupal\Core\StringTranslation\TranslationInterface;
+
+/**
+ * Exception thrown if Drupal is installed already.
+ */
+class SettingsAlreadyExistsException extends AlreadyInstalledException {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(TranslationInterface $string_translation) {
+    $this->specificMessage = 'Configured settings.php already exists.';
+
+    parent::__construct($string_translation);
+  }
+
+}