diff --git a/src/main/java/com/raoulvdberge/refinedstorage/apiimpl/network/grid/ItemGridHandler.java b/src/main/java/com/raoulvdberge/refinedstorage/apiimpl/network/grid/ItemGridHandler.java
index c1e6af1ca..f09850aa8 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/apiimpl/network/grid/ItemGridHandler.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/apiimpl/network/grid/ItemGridHandler.java
@@ -123,9 +123,15 @@ public class ItemGridHandler implements IItemGridHandler {
         ItemStack stack = network.getItemStorageCache().getList().get(hash);
 
         if (stack != null) {
-            ICraftingTask task = new CraftingTask(network, stack, network.getPattern(stack), quantity);
-            task.calculate();
-            RS.INSTANCE.network.sendTo(new MessageGridCraftingPreviewResponse(task.getPreviewStacks(), hash, quantity), player);
+            Thread calculationThread = new Thread(() -> {
+                ICraftingTask task = new CraftingTask(network, stack, network.getPattern(stack), quantity);
+
+                task.calculate();
+
+                RS.INSTANCE.network.sendTo(new MessageGridCraftingPreviewResponse(task.getPreviewStacks(), hash, quantity), player);
+            }, "RS crafting calculation");
+
+            calculationThread.start();
         }
     }
 
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/gui/grid/GuiCraftingStart.java b/src/main/java/com/raoulvdberge/refinedstorage/gui/grid/GuiCraftingStart.java
index 11bc8e427..3d220025d 100755
--- a/src/main/java/com/raoulvdberge/refinedstorage/gui/grid/GuiCraftingStart.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/gui/grid/GuiCraftingStart.java
@@ -125,6 +125,8 @@ public class GuiCraftingStart extends GuiBase {
 
         if (quantity != null && quantity > 0) {
             RS.INSTANCE.network.sendToServer(new MessageGridCraftingPreview(stack.getHash(), quantity));
+
+            startButton.enabled = false;
         }
     }