Broward County HVHZ | Window Installation

Locked in Place: Window Frame Anchoring

A window is only as strong as the anchors holding it. When anchors fail, the whole window blows out, frame and all. Here is how to make sure yours stay put.

Max Anchor Spacing

1.25"

Min Embedment

Typical Per Window

Calculate Anchor Requirements See Anchor Types

Window Frame Anchor Placement

6" O.C.

Total Anchors Required

16 anchors

Anchor Types

Know Your Window Anchors

Different walls need different anchors. Use the wrong one and it will not hold.

Tapcon Screws

Self-tapping concrete screws. Good for solid concrete or CMU block.

Min. 3/16" x 2-1/4"

Sleeve Anchors

Expansion anchors for concrete. Expand as you tighten the nut.

Min. 1/4" x 2-1/4"

Wedge Anchors

Heavy duty expansion anchors. Best for solid concrete, not block.

Min. 1/4" x 2-1/4"

Structural Screws

For wood framing. GRK or similar with at least 1-1/2" penetration.

Min. #10 x 3"

Interactive Tool

Anchor Spacing Calculator

Adjust the sliders to see how many anchors your window needs.

Enter Window Dimensions

Window Width 36"

Window Height 48"

Anchor Spacing 6"

Total Anchors Needed

Based on 6" spacing

Installation Guide

Proper Anchor Installation Steps

Follow these steps to ensure your anchors hold in a hurricane.

Check the NOA First

Your window's Notice of Acceptance tells you exactly what anchor type, size, and spacing to use. Do not guess.

Pre-Drill Properly

Use the right size drill bit for your anchor type. Too big and it will not hold. Too small and it will not go in.

Start From Corners

Place your first anchors 3-4 inches from each corner. Corners see the highest stress during wind events.

Space Evenly Between

Measure and mark your anchor locations before drilling. Even spacing means even load distribution.

Check Embedment Depth

Anchors need to go deep enough into solid material. 1-1/4" minimum in concrete, 1-1/2" in wood.

Do Not Overtighten

Overtightening strips out concrete or cracks the window frame. Snug plus a quarter turn is usually enough.

Common Questions

Window Anchoring FAQs

How far apart should window anchors be in Broward County?

In the HVHZ, window anchors are typically required every 6 inches on center for the jambs and sill. The exact spacing depends on the window size and design pressure. Larger windows or higher pressures need closer spacing. Always check the NOA for your specific window.

What type of anchors are required for impact windows?

The NOA (Notice of Acceptance) for your specific window specifies the anchor type. Common options include tapcon screws, sleeve anchors, or wedge anchors into concrete, and structural screws into wood framing. Always follow the NOA requirements exactly.

Why do windows blow out during hurricanes?

Windows usually blow out because the anchors fail, not the glass. When anchors are too far apart or too short, the frame flexes and pulls away from the wall. Once one anchor fails, the others get overloaded and fail in sequence. This is why proper spacing is so important.

What is the minimum embedment depth for window anchors?

For concrete or masonry, anchors typically need 1-1/4 inch minimum embedment. For wood framing, you need at least 1-1/2 inches into solid wood. Check your window NOA for exact requirements as they vary by product and design pressure.