diff --git a/build.gradle b/build.gradle
index b98fafc..ec7edb5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -29,6 +29,9 @@ sourceSets {
 	}
 }
 
+srcCompat = JavaVersion.VERSION_1_8
+targetCompat = JavaVersion.VERSION_1_8
+
 
 minecraft {
     version = "1.9.4-12.17.0.1962"
diff --git a/src/java/mmm/deco/DBlockChair.java b/src/java/mmm/deco/DBlockChair.java
index 3169084..13b516e 100644
--- a/src/java/mmm/deco/DBlockChair.java
+++ b/src/java/mmm/deco/DBlockChair.java
@@ -5,6 +5,7 @@ import java.util.List;
 
 import mmm.utils.I_UBlockSeat;
 import mmm.utils.I_URecipeRegistrar;
+import mmm.utils.I_USupportBlock;
 import mmm.utils.UMaths;
 import mmm.utils.URegistry;
 import mmm.utils.USeat;
@@ -21,7 +22,6 @@ import net.minecraft.creativetab.CreativeTabs;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.init.Blocks;
 import net.minecraft.init.Items;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.BlockRenderLayer;
@@ -218,29 +218,13 @@ public class DBlockChair
 	public void neighborChanged( final IBlockState state , final World worldIn , final BlockPos pos ,
 			final Block blockIn )
 	{
-		if ( !this.checkSupportBlock( worldIn , pos ) ) {
-			this.dropBlockAsItem( worldIn , pos , state , 0 );
-			worldIn.setBlockToAir( pos );
-		}
+		I_USupportBlock.dropIfUnsupported( state , worldIn , pos , this );
 	}
 
 
 	@Override
 	public boolean canPlaceBlockAt( final World worldIn , final BlockPos pos )
 	{
-		return super.canPlaceBlockAt( worldIn , pos ) && this.checkSupportBlock( worldIn , pos );
-	}
-
-
-	private boolean checkSupportBlock( final IBlockAccess worldIn , final BlockPos pos )
-	{
-		final BlockPos down = pos.down( );
-		final IBlockState downState = worldIn.getBlockState( down );
-		if ( downState.isSideSolid( worldIn , down , EnumFacing.UP ) ) {
-			return true;
-		}
-
-		final Block downBlock = downState.getBlock( );
-		return downBlock == Blocks.GLASS || downBlock == Blocks.STAINED_GLASS;
+		return super.canPlaceBlockAt( worldIn , pos ) && I_USupportBlock.check( worldIn , pos );
 	}
 }
diff --git a/src/java/mmm/deco/DBlockTable.java b/src/java/mmm/deco/DBlockTable.java
index 9ee20c2..1ffdc1c 100644
--- a/src/java/mmm/deco/DBlockTable.java
+++ b/src/java/mmm/deco/DBlockTable.java
@@ -4,6 +4,7 @@ package mmm.deco;
 import java.util.List;
 
 import mmm.utils.I_URecipeRegistrar;
+import mmm.utils.I_USupportBlock;
 import mmm.utils.UMaths;
 import mmm.utils.URegistry;
 import net.minecraft.block.Block;
@@ -266,8 +267,25 @@ public class DBlockTable
 
 
 	@Override
-	public boolean isSideSolid( IBlockState base_state , IBlockAccess world , BlockPos pos , EnumFacing side )
+	public boolean isSideSolid( final IBlockState base_state , final IBlockAccess world , final BlockPos pos ,
+			final EnumFacing side )
 	{
 		return side == EnumFacing.UP;
 	}
+
+
+	@Override
+	public void neighborChanged( final IBlockState state , final World worldIn , final BlockPos pos ,
+			final Block blockIn )
+	{
+		I_USupportBlock.dropIfUnsupported( state , worldIn , pos , this );
+	}
+
+
+	@Override
+	public boolean canPlaceBlockAt( final World worldIn , final BlockPos pos )
+	{
+		return super.canPlaceBlockAt( worldIn , pos ) && I_USupportBlock.check( worldIn , pos );
+	}
+
 }
diff --git a/src/java/mmm/utils/I_USupportBlock.java b/src/java/mmm/utils/I_USupportBlock.java
new file mode 100644
index 0000000..000cbd8
--- /dev/null
+++ b/src/java/mmm/utils/I_USupportBlock.java
@@ -0,0 +1,40 @@
+package mmm.utils;
+
+
+import net.minecraft.block.Block;
+import net.minecraft.block.state.IBlockState;
+import net.minecraft.init.Blocks;
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.IBlockAccess;
+import net.minecraft.world.World;
+
+
+
+public interface I_USupportBlock
+{
+
+	public static boolean check( final IBlockAccess worldIn , final BlockPos pos )
+	{
+		final BlockPos down = pos.down( );
+		final IBlockState downState = worldIn.getBlockState( down );
+		if ( downState.isSideSolid( worldIn , down , EnumFacing.UP ) ) {
+			return true;
+		}
+
+		final Block downBlock = downState.getBlock( );
+		return downBlock == Blocks.GLASS || downBlock == Blocks.STAINED_GLASS || downBlock instanceof I_USupportBlock;
+	}
+
+
+	public static boolean dropIfUnsupported( final IBlockState state , final World worldIn , final BlockPos pos ,
+			final Block block )
+	{
+		final boolean rv = !I_USupportBlock.check( worldIn , pos );
+		if ( rv ) {
+			block.dropBlockAsItem( worldIn , pos , state , 0 );
+			worldIn.setBlockToAir( pos );
+		}
+		return rv;
+	}
+}