
Double Slabs
Allows vanilla and modded slabs to be combined and placed vertically
Screenshots

About this Mod
Double Slabs
For the longest time I've been mildly infuriated by Minecraft slabs. Why on earth can't we place different types of slabs on top of each other??!! It makes zero sense to me so that's why I created this mod.
Double slabs is all about improving the vanilla and modded slabs through minor tweaks to their behaviour.
Features
- Mixed Double Slabs - Have you ever wanted to place two slabs of different slab types on top of each other?? Well now you can!
- KleeSab like behaviour on Mixed Double Slabs (or two double slabs which are of the same type if the replace same type option is true). This means that slabs now break separately when mining a double slab and the speed of mining of the individual slab depends on which slab you are looking at and which tool you are using. For example: if you have a mixed oak slab and stone slab, trying to mine the oak slab with a pickaxe will be quite slow but mining the oak slab with an axe will be quicker and vice versa. This a survival mode feature only.
- Vertical slabs (excluding 1.21 versions) - Simply hold sneak when holding a regular slab to place a vertical version! This also works with combining two vertical slabs including vertical slabs from Quark, just ensure you are not holding sneak to combine!
- Mod Compatibility - both the mixed double slab and vertical slab feature works with many other mods. Some mods require additional work to be supported.
Can I use this in my modpack?
Of course! This is the main reason I made this mod!
Showcase your creation here!
The popularity of this mod has blown me away (thank you so much!), so if you've created something using Double Slabs, be sure to send me a private message with an image and I might showcase your creation here! I'm sure you're all much better builders than I am!
Available Versions
How to Install Double Slabs on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.1).
Install Mod
Open the mod browser in the dashboard and search for "Double Slabs". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.1, 1.20.1, 1.19.4 (+26 more)
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Double Slabs server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.1). You can switch loaders with one click in the panel.
Is Double Slabs compatible with fabric and forge and neoforge?
Double Slabs officially supports fabric, forge, neoforge for Minecraft 1.21.1, 1.20.1, 1.19.4. Note: Forge and Fabric mods are NOT cross-compatible – pick one loader and stick with it. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Double Slabs – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Double Slabs consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
Similar Mods
Rent Modded Server
Install Double Slabs with just one click on your server.