Products / Insulation Systems / AutoCeil™

Advanced Metal Building Design


AutoCeil™ is a safer, faster and ideal method of installing ceiling and wall liners in buildings to support metal building insulation and finish interiors. AutoCeil requires ceiling support struts, provided by the metal building manufacturer, to provide a support platform for the AutoCeil sheet with insulation as well as to transfer rafter brace loads from the purlins to the struts.

Thermal Design will assist building manufacturers with questions and requirements. If a building manufacturer will not fulfill the specifications, please contact Thermal Design and we will assist builders with alternative building manufacturer referrals that will meet AutoCeil specifications. Thermal Design manufacturers the AutoCeil System and provides all components required to complete the installation for buildings that are ordered to the specifications.

Faster Metal Building Erection

  • Fewer parts and pieces with strut rafter bracing vs. traditional rafter bracing to purlin.
  • Struts are designed to erect the building faster.
  • No straps or bands required and no bottom side ceiling fasteners needed.
  • Unfaced blanket insulation is simply sliced around purlin stiffener braces in cavity.
  • 80% fewer vapor retarder field seams compared to laminated fiberglass insulation.

Save Equipment and Labor

AutoCeil Does Not  Require a Lift
Interior lifts are not required for the ceiling installation, as work may be done from top side and from the floor. Purlin bundles may be placed on rafters and walked out and bolted up independently of setting the rafters, struts, cross bracing and squaring building; resulting in significant crane and lift rental savings on projects.

The following modifications are required for AutoCeil installation:

  1. Add Ceiling Support Struts
  2. Rafter Brace Loads from Purlins to Struts
  3. Base Channel on Exterior Walls

1. Adding Ceiling Support Struts

Series of steel support struts are required spanning between adjacent rafters that are engineered and provided as an integral component of the building. Support struts are required at uniform 10' spacings from the center of the ridge strut down to each sidewall with those nearest the walls being the variable space.

  • Intermediate Strut -  placed 10' on  center starting from the ridge line or high side.
  • Ridge Strut - placed approximately in the center of the ridge purlin space.
  • Inside Corner Strut - placed to align with the inside steel line of the wall girts.

AutoCeil Advanced Building Design

2. Rafter Brace Loads from Purlins to Struts

Rafter flange bracing loads are engineered to be removed from the purlins and applied directly to the ceiling support struts by design. Preferred if purlins are not placed directly, in line above support struts.

The slightly modified design and engineering allows the AutoCeil system to be easily mechanically pulled throughout ceiling plane without bracing interference.

Rafter flange brace bolted to open web rafter and to ceiling support strut for fast and clean connections.
Reduce the quantity of braces by attaching to struts (10' oc) compared to attaching to purlins (5 oc' or less).

AutoCeil Sheet Pulled Over RafterPlacement of the rafter flange bracing to the bottom of support strut allows the AutoCeil sheet and AutoCeil Pull Tube to be pulled throughout ceiling plane without obstructions.

Offset Distance

Offset distance between the top plane of the struts shall be offset 2 inches below a line formed by the top plane of the rafter flange unless otherwise specified. Insulation cavity depth is created with this placement of the struts within the rafter web. 

AutoCeil Roof Rafter Brace

Vertical mounting plate welded to the strut end and projecting from each end of the strut tube for mounting the strut end to a vertical stiffener plate welded between the upper and lower rafter flanges.


Ceiling support struts are recommended to be hot rolled square tubing. The surface condition of the top, flat plane should be smooth and free of projections, welding spew and sharp edges.


Purlin Clips on Rafters

Ideally purlin clips are slightly narrower than the width of the top rafter flange, allowing for a small rafter flange top edge for easy sealing of the AutoCeil Sheet edges continuously along the rafters. Alternatively, AutoCeil Sheet edges are trimmed to fit neatly around the purlins on the top side of the rafters and sealed between the purlins continuously (Option: Simple Saver Air Tight™ Sealant at the purlin rafter intersections).

3. Base Channel on Exterior Walls

By-pass mounted wall girts shall be ordered allowing space for full thickness metal building insulation to be installed between the wall panel and the building column. Base channel, secured by lag bolts or anchor bolts, is the preferred method for attachment for side walls and end walls.

AutoCeil, Column, Rafter, Base Channel
Call 800.255.0776
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