# Best practices for using ground pours on 4-layer PCBs with internal planes

**URL:** <https://sierraconnect.protoexpress.com/t/best-practices-for-using-ground-pours-on-4-layer-pcbs-with-internal-planes/3624>\
**Category:** Design and Layout\
**Tags:** grounding\
**Created:** [October 8, 2025, 3:32pm UTC](https://sierraconnect.protoexpress.com/t/best-practices-for-using-ground-pours-on-4-layer-pcbs-with-internal-planes/3624 "2025-10-08T15:32:59Z")\
**Posts on this page:** 1\
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**Author:** ![timothy.phillips](https://avatars.discourse-cdn.com/v4/letter/t/d78d45/32.png) [@timothy.phillips](https://sierraconnect.protoexpress.com/u/timothy.phillips)\
**Post date:** [October 8, 2025, 7:54pm UTC](https://sierraconnect.protoexpress.com/t/best-practices-for-using-ground-pours-on-4-layer-pcbs-with-internal-planes/3624/2 "2025-10-08T19:54:37Z")

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> [@Should empty spaces on a 4-layer PCB be filled with ground?](https://sierraconnect.protoexpress.com/t/should-empty-spaces-on-a-4-layer-pcb-be-filled-with-ground/2858):
>
> For a 4-layer PCB with the following stack-up: Layer 1: High-speed signal Layer 2: Dedicated ground plane Layer 3: Power plane (5V, 3.3V, 1.8V) Layer 4: Normal-speed signal On single/double-layer boards, the usual practice is to fill all unused space with ground. Since a dedicated ground plane already exists on Layer 2, is it still beneficial to fill the empty spaces on Layer 1 and Layer 4 with a ground pour? Would this improve signal integrity, or could it introduce potential issues?

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