Elevation not working on a LinearLayout

Just make CardView as parent of your LinearLayout and you can achieve elevation.

<android.support.v7.widget.CardView 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    card_view:cardUseCompatPadding="true"
    card_view:cardElevation="4dp"
    card_view:cardCornerRadius="3dp">

       <LinearLayout
              android:id="@+id/panelAddress"
              xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:background="@drawable/button_flat_white"
              android:orientation="vertical"
              android:padding="20dp">  

            //some content
      </LinearLayout>
 </android.support.v7.widget.CardView>

As described here https://stackoverflow.com/a/27518160/2481494 there are several requirements so that the shadow is drawn:

• Space for the shadow in the parents view Group. As bleeding182 mentioned, padding can cause the shadow to be clipped:

  (Do NOT use a padding. A padding on the framelayout will also cut the shadow off)

  However, this can be fixed with android:clipToPadding="false" in the parent.

• The elevated view needs to have a background to cast a shadow. Without information about your @drawable/button_flat_white I can't tell whether this is a problem in your case.

To solve your problem you should modify your FrameLayout like this:

<FrameLayout
        android:id="@+id/fragment_container_top"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"

        android:clipToPadding="false"
        android:paddingBottom="10dp"/>

To check whether your @drawable/button_flat_white causes any problems try to change the background of your LinearLayout to a simple color temporarily:

<LinearLayout
    android:id="@+id/panelAddress"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:elevation="10dp"
    android:orientation="vertical"
    android:padding="20dp"

    android:background="#fff">  
//some content
</LinearLayout>