[Home] [Top Bar Hive] CalKenyan 4 Building Instructions
Copyright 2002 by Leonard G. Barton - rights released for noncommercial use.


My Latest Top Bar Hive (KTBH), the CalKenyan 5 (Kenyan hive adapted for California).

First Pictures

The landing porch is at the lower right of the hive. The blue stripes are to aid the bees in locating the entrance. Any distinctive pattern and color may be used for this "address" and should vary between hives used near to each other. [Over_View]

These pictures show some details specific to the latest hive. This is a modification of the previous version, the CalKenyan 4 (CK4). The CK4 was a 22 degree Kenyan with bottom mite screen, bottom closure panel, and low entrance on one end.

Old Side Angle

This version returns to the earlier hive's angle of about 30 degrees from vertical. With this narrow angle the sides may be extended to form a narrow bottom slot (but not as narrow as CK3), which need not be closed in winter, as it prevents drafts while still allowing ventilation. With no bottom closure there is no messy bottom board to clean. All small detrius simply falls to the ground where it is cleaned up by ants and soil bacteria. The bees need only remove dead and damaged bees and failed brood from the screened area and it expected that most of those will fall onto the porch or near the entrance where they are easily removed. In the warmer months german wasps (yellowjackets) feast on these leavings.

Wood Ends Supporting Legs

The hive body design and leg mounting method continue the structural design theme of CK3 and CK4. [Bare_End]

No Paint

Rather than paint the body, the ends are covered with corrugated polyethelyne. If you elect to paint the exterior portions of the ends use a non-sealing primer and paint, otherwise it will tend to blister and peal due to the interior moisture. [Covered_End]

Gypsum Board Cores Under Poly

The sides are light wood frames each filled with a panel cut from 5/8 gypsum board (drywall), rather than the cardboard of CK3 and CK4. This is to get increased thermal mass and humidity stability , emulating the daub and wattle (mud and twigs) construction seen in some african hives. The panels are sheathed with poly inside and out. The gypsum board allows the poly to be stapled down if it should warp. The liner was installed under warm conditions to avoid this warpage and is currently stapled only at the edges.

Gypsum board tends to warp under gravity if it gets too damp. Should this occur in use I am prepared to add external battens to support the sides.

New Fabrication Sequence Required

In the previous version the outer liners were attached to the side frames, the legs installed, and the interior of the hive was then completed. In this hive it is difficult to staple the inner liners near the lower apex after hull assembly so this is now done first, when prefabricating the sides.

After initial hull assembly the hull is inverted and the gypsum board core (or cardboard if used) and the outer poly are attached.

The legs are attached after completion of the hull.

Bar Design

Shallow Web Wide Bars

These bars are 24 inches overall with a 22 inch inside exposure. They are 1.5 inches wide (37.5mm), wider than the usually recommended 35mm (for European bees). I have found that bees will draw deep comb for honey stores. If a 35mm bar is used the deep stores comb at the top of one bar may interfere with the placement of comb on the adjoining bar, which will lead to skewed comb. 1.5 inches is a also convenient width if the bars are ripped from a finished U. S. standard 2 by 4, which is 3.5 by 1.5 inches.

The bars use a shallow web and five degree angled exposure. They are proving sucessful in use as the bees start comb on the protrusion (which is rubbed with wax) and any skewing is easily corrected by cutting and pushing as the comb is extended toward the bar ends.

The bars should be uniform where the angled cheeks meet so that there is not a step between bars. The bees tend to build comb where it is easy to hang on and so will usually start at the shallow web rather than the edge. When comb is in early development they may also start comb at the edge of the bar, especially if there is a gap or step there. These false combs should be promptly removed (you can work them onto the web of an undeveloped bar if they are small). The bees will draw honey stores much deeper than brood and tend to store at the top of brood combs and so will extend the comb to form a single bee space between combs at the top, eventually eliminating any opportunity to place comb at the edge of the bars.

Seen at the left below, a blank ready for the final angled cuts and to the right a finished bar, both upside down. With a careful saw setup it should be possible to eliminate the vertical cuts.

These very shallow webs encourage prompt attachment of new comb to the angled cheeks on each side of the web, which makes a much more durable comb at this early stage of development.


Click Here for bar fabrication instructions. If you do not feel comfortable using power tools there are alternative methods available. Be sure to leave free space at the end of the hive - if wood bars are packed tightly they can swell under humid conditions and damage the hive (wood swells more readilly across the grain). With deep webs (1 inch) the bees tend to make galeries behind the comb and downward angled cells at the top of the comb as seen below. These flaws were eliminated in subseqent comb development by reducing the web depth to 1/4 inch.


The bars also are made with a slot to receive a spline, so that any bar may be used as a wild comb or broken comb bar, simply by tying in a narrow spline made from 1/8 inch (3mm) fiberboard. (I tried wood, but it is difficult to get a uniform stiffness, and so it is difficut to get a proper curve.) These splines are 32 inches (82cm) long and about 3/4 inch (18mm) wide. The splines are precut and kept ready for use if needed. To make a bar ready for use it is placed into the bar cuts and the lower portion only is briefly soaked in water. This allows the lower portion to take on a greater curvature so that the upper portions conform to the the 30 degree angle of the hive sides rather than touching them, leaving only a bee space.

If you cut several slots you can use a shorter spline to accomodate smaller comb.

When used to support wild comb the splines are notched about an inch from the ends and tied to the bar with string.

As an experiment, several bars have been prepared with narrow splines (1/4 inch) to see if new comb will be attached to and strengthend by the spline. This was suggested by a bamboo top bar described on a web page. After experimenting, this method is not recommended - comb breakage is better reduced by restricting its vertical extent with a screen or grid.


Using Wild Comb

Below is a picture of an earlier bar design with a spline supporting wild comb tied in with cotton string. This comb was removed from a loudspeaker that was hanging in a covered patio. The comb was quickly attached to the bar throughout the upper edge and at a few points on the spline. The bees also glued the spline to the bar with propalis. Remove any remaining string when the comb is secure. Do not use polyester thread (such as dental floss) as the bees can get tangled and trapped in the fuzzy mess remaining after they chew it apart.


When using splines to support wild comb it is important that they be removed once the comb is secured to the top bar. If it is not removed the bees can create doubled comb as they prefer to start comb at the edge of the spline.

Correcting Skew

A picture of a developing bar with a skew - note that the attachment closest to the camera is approaching the edge of the bar.


The skewed portion has been cut loose with a hacksaw blade and pushed into alignment. The bees will rapidly reattach the comb. Wax near the edge is cleaned off the bar. [Deskewed_Comb]

Skewing can occur even with deep web bars, but is much easier to correct with the shallow web bars shown here. Correction should be done early in comb development so that the correction will not result in insuffient "bee space" between combs.

Bottom Slot and Entrance

The entrance is via a portion of the bottom slot. The remainder of the slot is closed with 8 mesh screeen so that the bees do not have to defend this area and moths are discouraged. Mites and wax dropping will fall through this screen.


This entrance is expected to aid in supering as the bees will enter, walk up the side to the top bars and thence through bar gaps (to be shown later) into the super area. These bar gaps will be covered in cold weather. The porch is close to one end of the hive rather than in the middle, this so that the brood chamber (usually near the entrance) will be on one end, with the remaining space for honey stores. (Given the arrangement of my beeyard I should have put the porch on the other end.) [Entrance_Porch]

Porch Mounting

Eliminating fabrication and painting of wood parts this porch is also sheltered from rain and dew, a hazzard to the bees in the early morning. The need to rout or drill the end panel is also eliminated.

Bare copper wire is used to make brackets for the porch. These are inserted into the corrugations of the side extension and porch. [Porch_Brackets]

Side Extension

In the area of the landing porch one side extends below the hive so that anything falling down the opposite side will land on this extention, rather than on the landing porch. Below is an interior view of the transition from screened bottom to entrance slot. The side extention is on the right end of the back wall. Only one side is so extended. [Interior_View]

Below is an exterior view (the hive has been rolled over) of the transition from screened bottom to entrance slot. The blue portion is the inner liner extension. Copper wire links are used to attach the landing porch. [Exterior_View]

Landing Porch Gap

A small gap between the landing porch and the side extension allows small detrius to continue to the ground, while bees can easily cross the gap and climb up the side, which has been lightly sanded to give the bees a grip for their hooked feet. They will eventuall cover the entire interior with a thin coat of propalis. [Porch_Gap]

And a closer view: [Porch_Gap_Detail]

Part Depth Partition

The usual movable partion extends to the styrene light diffuser hanging grids.


Hanging Grids

These grids restrict the depth of comb and allow introduction of new bees using the newspaper method. [Hanging_Grid]

Back Cover

A cover substitutes for bars at the back of the hive to aid in maintaining warmth in cold weather. Top closure is necessary to exclude wax moths. I may cut a hole and attach screening for summer use. [Inner_Cover]

The white bars shown are folded courugated poly with styrene reenforcements. These should not be interspersed with wood bars as they tend to sag and leave gaps if next to bars that do not sag. The plastic bars have the advantage of not swelling in humid conditions. The swelling and shrinking of wood bars leads to propalis buildup and causes the bars to move. You must leave additional space without bars at the back of hive - the swelling can tear the hive apart. The poly panel is flexible enough to not apply pressure to the hive body.


A foil lined poly roof similar to that shown in the CK4 construction page is used on this hive as it has proven to keep the hive cool in full sun exposure. Picture taken prior to installation of ventilation cupola.


Venting Cupola

A screened and foil lined cupola has been added to remove hot air from the attic.


Continuing development

A second hive is now complete that uses a different end structure, reducing the amount of wood and making the structure more suitable for a kit. This hive was made considerably shorter to fit an existing roof and is suitable for use as a double nuke (two small hives with a full depth partition). It appears that a hive interior length of about 40 inches, which accomodates 24 bars, a movable end wall and some free space is an appropriate size for a hobby hive.

More to come

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